Research Article Preparation, and Structural and Magnetic …downloads.hindawi.com/archive/2014/184340.pdf · 2019-07-31 · Research Article Preparation, and Structural and Magnetic

Research ArticlePreparation and Structural and Magnetic Properties of CaSubstituted Magnesium Ferrite with Composition MgCaxFe

2minusxO4

(119909 = 000 001 003 005 007)

K K Bamzai1 Gurbinder Kour1 Balwinder Kaur1 and S D Kulkarni2

1 Crystal Growth amp Materials Research Laboratory Department of Physics and Electronics University of JammuJammu 180006 India

2National Chemical Laboratory Homi Bhabha Road Pashan Pune 411008 India

Correspondence should be addressed to K K Bamzai kkbamzyahoocom

Received 10 December 2013 Revised 24 March 2014 Accepted 29 March 2014 Published 22 April 2014

Academic Editor Christian M Julien

Copyright copy 2014 K K Bamzai et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Calcium substituted magnesium ferrite with composition MgCa119909Fe2minus119909

O4(where 119909 = 000 001 003 005 007) was prepared

by ceramic technique These compositions were then subjected to detailed study for structural and magnetic properties X-raydiffraction studies reveal the formation of single phase cubic spinel The values of lattice constant increase with the increase incalcium concentration from 119909 = 000 to 119909 = 003 and then decrease Scanning electron microscopic (SEM) technique was used tostudy the morphology of the grown materials The grain size was calculated using average intercept line method The elementalcomposition of pure and calcium substituted magnesium ferrite was obtained from energy dispersive X-ray analysis (EDAX)spectrum The hysteresis loop confirms the magnetic behaviour of the prepared composition which is then discussed on thebasis of cation distribution The parameters such as saturation magnetization coericivity and retentivity are calculated The Curietemperature was found to decrease with increasing calcium content

1 Introduction

Magnesium ferrite has attracted attention as one of theferrites for high density magnetic recording microwaveabsorbents sensors and electronic device high frequencydevices colour imaging and so forth because it has highmagnetic permeability and high electrical resistance [1ndash4]MgFe

2O4is a partially inverse spinel [5 6] and can be con-

sidered as a collinear ferrimagnet whose degree of inversionis sensitive to the sample preparation history Magnesiumferrite with diamagnetic substitution for Mg2+ and Fe3+ ionshas attracted the attention of a number of research workerswho attempted to explain the magnetic properties on thebasis of the distribution of the only magnetic ion Fe3+ intetrahedral (A) and octahedral (B) sites which makes theanalysis reliable [7] The physical and chemical propertiesof MgFe

2O4depend upon the cation distribution which in

turn is a complex function of processing parameters andmethod of preparation of the material [8] The variation that

is brought about in the physicochemical and electromagneticproperties due to a change in the particle dimension hasencouraged many researchers around the globe to preparespinel ferrites with novel properties

The structural and magnetic characteristics of MgFe2O4

with nonmagnetic substitution such as Zn2+ [9] Cd2+ [10]Ti4+ [11] and Al3+ [12] have been investigated by means of X-ray diffraction (XRD) andmagnetic measurement techniqueSome work on various properties of spinel ferrites with Ca2+substitution such as CoFe

2O4[13] Li-Zn ferrite [14] Cu-Zn

ferrite [15] Ni-Zn ferrite [16] andMgFe2O4[7] has also been

reportedGenerally Mg2+ and Fe3+ cations are distributed at both

sites The Fe3+A -Fe3+B super exchange interaction is normallydifferent from the Mg2+A -Fe3+B interaction so the variation ofcation distribution over A and B sites in the spinel leads todifferent magnetic properties of these oxides even thoughthe chemical composition of the compound does not change

Hindawi Publishing CorporationJournal of MaterialsVolume 2014 Article ID 184340 8 pageshttpdxdoiorg1011552014184340

2 Journal of Materials

[17] Thus determination of cation distribution between thetetrahedral and octahedral sites has been a subject of manystudies [18ndash21] Wei et al [18] from the X-ray diffractionstudies proposes that withmanganese ion substitutionMn3+ions predominately occupy the octahedral site whereas Fe3+ion decreases linearly thereby suggesting that Fe3+ is beingreplaced by Mn3+ ion on substitution

In the present paper calcium (Ca) substituted magne-sium ferrite is reported with a view to study the effect ofsubstitution of nonmagnetic ion (Ca2+) on the structuraland magnetic behaviour The free ionic radius of the cationsinvolved is Mg2+ (066 A) Ca2+ (099 A) and Fe3+ (064 A)Therefore it would be interesting to substitute large cationCa2+ (whose radius is near the threshold sim1 A) for Fe3+ inMgFe

2O4

2 Materials and Methods

21 Materials Preparation Pure magnesium ferrite (MgFe)and calcium substituted magnesium ferrite (CaMgFe) withcomposition MgCa

119909Fe2minus119909

O4(119909 = 000 001 003 005 007)

were prepared using the ceramic technique High purityoxides 9999 of CaO MgO and Fe

2O3 were used as

starting materials The oxides of metal ions were mixedtogether according to their molecular weight The mixture ofeach samplewas ground to a very fine powder in agatemortarThe mixed powder was then transferred to electric ball millfor 48 hours The dried powder was pressed into pellets andpresintered at a temperature of 800∘C for 2 hours with aheating rate of 2∘Cmin so that the initial chemical reactionbetween the constituents can take place The presinteredmixture was ground again and pressed into the requiredshapes using hydraulic press under a pressure of 120 kgcm2in order to obtain a high degree of compaction In the finalsintering process the samples were placed in a furnace heatedup to 1200∘C with a heating rate of 4∘Cmin kept for 2hours and then cooled to 900∘C at the rate of 75∘Cmin afterwhich it was cooled to room temperature After sintering thecompactswere polished to remove the surface layers to ensurethat the measured properties correspond to those of the bulkand not the surface layers

22 Characterization In order to confirm the completion ofsolid state reaction as well as analyzing the crystalline phaseand the structural parameters X-ray diffraction patterns ofthe powdered samples were recorded by using a Rigakupowder X-ray diffractometer using Cuk

120572(120582 = 154059 A)

radiation The shape size and distribution of pure andcalcium substituted magnesium ferrite were carried out withthe help of scanning electron microscope (SEM Model LEO440 PC Based DIGITAL SEM) The elemental compositionwas confirmed with the help of energy dispersive X-rayanalysis (EDAX model OXFORD LINK ISIS 300) A fullycomputer controlled vibrating sample magnetometer (VSMEGampG Princeton Applied Research Model 4500) was usedfor magnetization (with a maximum applied field of 15 kOerat room temperature) and Curie temperature measurements

Table 1 Variation of grain size with different composition of Cathat is MgCa

119909Fe2minus119909

O4 (where 119909 = 000 001 003 005 007)

Composition Size (120583m)Pure MgF 399Ca 1 326Ca 3 237Ca 5 167Ca 7 130

3 Results and Discussion

31 Structural Properties Figures 1(a)ndash1(e) show typical scan-ning electron microscopic (SEM) images of MgCa

119909Fe2minus119909

O4

(where 119909 = 000 001 003 005 007) respectively It isclear from these electron micrographs that the materialessentially consists of some irregularly cubic particles in pureMg-ferrite (Figure 1(a)) and agglomeration of these particlesincreases with the increase in Ca2+ ions concentrationThe grain size was calculated using the average interceptline (AIL) method [22] Well-crystallized dense grains ofirregular shapes were observed for these compositions withthe presence of large micropores The grain size of MgFe is399 120583m which decreases with increase in substitution Thecontinuous decrease in grain size with Ca substitution maybe due to the fact that Ca2+ ions (099 A) have large ionicradii than that of Fe3+ (064 A) and therefore show limitedsolubility in spinel lattice and prevent grain growth resultingin decrease in grain size [23] Table 1 shows the values of grainsize with Ca2+ composition in Mg-ferrite

Figures 2(a) and 2(b) show the energy dispersive X-rayanalysis (EDAX) spectrum for 1 and 7 Ca substituted mag-nesium ferrite whereas Table 2 gives quantitative estimationof elements obtained directly from spectrum through itsatomic and weight percentages The results confirmed thepresence of the required elements in the prepared compo-sition with almost all the peaks associated with elementssuch as those of Mg Fe O and Ca thereby suggesting theformation of pure MgFe and CaMgFe

The X-ray diffraction (XRD) studies confirm the forma-tion of polycrystalline cubic spinel phase Figure 3 showsX-ray diffraction pattern indicating (hkl) values for pureand Ca substituted magnesium ferrite The diffraction peakscorresponding to planes (220) (311) (400) (422) (511) and(440) provide a clear evidence for the formation of spinelstructure of the ferrite [24] The ldquo119889rdquo values and intensitiesof the observed diffraction peaks match the crystalline cubicspinel form of the magnesium ferrite (JCPDS Card no 36-0398)

The data on lattice parameter ldquo119886rdquo X-ray density ldquo119863119909rdquo

bulk density ldquo119863119861rdquo and porosity ldquo119875rdquo is summarized in Table 3

The plot of lattice constant ldquo119886rdquo (A) versus calcium content(119909) is depicted in Figure 4 It is found from the figure thatlattice constant initially increases up to119909= 003 and thereafterit decreases with further increase in ldquo119909rdquo This indicates thatthe variation of ldquo119886rdquo with ldquo119909rdquo does not obey Vegardrsquos law[25] This nonlinear behaviour of ldquo119886rdquo with ldquo119909rdquo may be

Journal of Materials 3

MgF

(a)

Ca 1

(b)

Ca 3

(c)

Ca 5

(d)

Ca 7

(e)

Figure 1 Scanning electron microscopic (SEM) photographs showing (a) pure MgFe2O4(MgFe) (b) 1 Ca substituted MgFe (c) 3 Ca

substitutedMgFe (d) 5 Ca substitutedMgFe and (e) 7 Ca substitutedMgFeThe agglomeration of particles increases with increase in Caconcentration

due to the substitutional effect of larger Ca2+ ions (099 A)in magnesium ferrite Further nonlinear behaviour of ldquo119886rdquowith ldquo119909rdquo on the other hand is reported for the systems whichare not completely normal or inverse [26] The Ca2+ ionshave strong preference for tetrahedral (A) site [27] The Ca2+ions having the larger ionic radius (099 A) when substitutedin Mg-ferrite replace the smaller Fe3+ (064 A) ions on thetetrahedral (A) sites this causes linear rise in the latticeconstant with ldquo119909rdquo following Vegardrsquos law for 119909 le 003 andthe maximum value of ldquo119886rdquo is observed for this composition(119909 = 003) The decrease in the lattice constant at 119909 ge 003can be attributed to the reduction of Ca2+ ions on the A-sites The continuous decrease of lattice constant till 119909 = 007suggests that there is continuous reduction of Ca2+ ions on

the A-sites of the cubic latticeThe deviation from the straightline thus also indicates incomplete Ca substitution in facecentered cubic (fcc) phase It is also reported in the literaturethatwhen doping percentage of Ca2+ ions is increased beyond005 the value of lattice parameter again decreases slightlyThis is probably due to the fact that for higher concentrationthe Ca2+ ions occupy interstitial sites [20 28]

The X-ray density (119863119909) was calculated using the relation

[29]

119863119909=8119872

1198731198863 (1)

where ldquo119872rdquo ldquo119873rdquo and ldquo119886rdquo are themolecular weight Avogadrorsquosnumber and lattice parameter respectively It is evident from


Table 2 Experimental values obtained from the spectrum of energy dispersive X-ray analysis for various constituent elements present inmagnesium ferrite and calcium substituted magnesium ferrite

Element MgFe (pure) MgFe (Ca 1) MgFe (Ca 3) MgFe (Ca 5) MgFe (Ca 7)At Wt At Wt At Wt At Wt At Wt

O 5765 3149 5839 3194 6013 3433 5643 3135 5666 3311Mg 1093 907 1016 844 1009 903 1154 974 1377 1223Fe 3093 5898 3062 5847 250 4982 2620 5080 1973 4025Ca mdash mdash 084 115 477 682 583 812 984 1441

Table 3 Lattice parameter ldquo119886rdquo X-ray density ldquo119863119909rdquo bulk density ldquo119863

119861rdquo and porosity ldquo119875rdquo for different composition

Composition Lattice parameterldquo119886rdquo (A)

X-ray densityldquo119863119909rdquo (gmcm3)

Bulk density ldquo119863119861rdquo

(gmcm3) Porosity ldquo119875rdquo ()

MgF (Pure) 83848 45062 3864 15Ca 1 84108 44610 3598 19Ca 3 84405 44071 3225 26Ca 5 84211 44783 3692 17Ca 7 84046 44721 4061 9

Table 4The values of saturationmagnetization (119872119904) coercivity (119867

119888) residual magnetization (119872

119903) and Curie temperature (119879

119862) for pure and

substituted MgF

Number of Ca atomssubstituted

Saturationmagnetizationldquo119872119904rdquo (emug)

Coercivity ldquo119867119888rdquo

(Oer)

Residualmagnetizationldquo119872119903rdquo (emug)

Curie temperatureldquo119879119862rdquo (∘C)

000 235 26 152 400001 225 28 153 388003 245 31 200 370005 307 205 138 331007 290 30 196 325

the table that X-ray density decreases up to 119909 = 003 and thenincreases which is attributed to the variation of ldquo119886rdquo with ldquo119909rdquo[30] The change in density is divided into two regions Inthe first region for the composition 119909 = 000 to 003 thereis decrease in the density whereas in the second region thedensity increases This behaviour starting from 119909 = 003 to007 [31] cannot only be ascribed to the replacement processbetween the lighter atom of Fe by the heavier atom of Ca butalso be according to the distribution of Ca content among thesublattice and consequently the effect of condensation on thecrystal structure By comparing the bulk density and X-raydensity porosity of each composition can also be calculated

The percentage porosity of the samples is calculated usingthe relation [32]

119875 = 1 minus 119863119861119863119909

(2)

where ldquo119863119861rdquo and ldquo119863

119909rdquo are the bulk and X-ray density

respectively

32 Magnetic Properties It is well known that calcium ionscan enter the spinel lattice up to a certain proportion [21]and its solubility limit is determined by the following threefactors (i) relatively larger ionic radius of Ca2+ ion [23] (as

compared to the dimensions of A-tetrahedral or B-octahedralsites) (ii) the lattice constant of the spinel substituted byCa and (iii) the cooling rate of the ferrite after sintering[21 33 34]Therefore it is necessary to understand from theirmagnetic properties the behaviour of calcium substitution onthe spinel lattice of MgFe

Figure 5 displays the room temperature hysteresis loopsfor pure and Ca substituted MgFe which indicates thesoft ferrimagnetic nature of the synthesized particles Thevalues of the saturation magnetization (120590

119904) coercivity (119867

119888)

and retentivity (120590119877) can be obtained from this curve It is

clear from the figure that all the materials show a similarbehaviour that is the value of magnetization increases withthe increase in the value of applied field and gets saturatedat a very low value of applied field approximately equal to1000Oer From these hysteresis loops one can obtain theinformation about the saturation magnetization (120590

119904) and

the same is given in Table 4 The interesting observation isthat the value of saturation magnetization is maximum inthe sample for Ca5 substitution and minimum for Ca1substituted MgFe

The value of saturation magnetization in pure MgFe2O4

is 235 emugm which decreases to 225 emugm for Ca1and then starts to increase with 245 emugm for Ca3 and


CaCa

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

4000

3000

2000

1000

0

5 10

Energy (keV)

(a)

Ca

Ca

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

3000

2000

1000

0

5 10

Energy (keV)

Ca

Ca

CaCaCaCaCaCaCaCaCaCaCaCaaCa

Mg

O

Fe

Fe

FeFFFFFFFFFF

(b)

Figure 2 Energy dispersive X-ray analysis (EDAX) spectrum for (a)1 Ca substituted and (b) 7 Ca substituted MgFe showing all theconstituent elements expected to be present in the preparedmaterial

307 emugm for Ca5 followed by further decrease with290 emugm for Ca7 substituted magnesium ferrite Smitand Wijn [35] have reported saturation magnetization valuefor bulk particles of MgFe

2O4as 27 emugm whereas in the

present case the value comes out to be 235 emugm Thedifference in the value of saturation magnetization can beexplained in the light of cation distribution Any change inthe concentration and nature of ions in A- and B-site causesresultant magnetization to be different from the reported one[1]

The composition dependence of magnetization can beexplained on the basis of cation distribution It is reported[35] that the metal ion distribution in MgFe

2O4is given by

(Mg01Fe09)A[Mg

09Fe11]B (3)

20 30 40 50 60 70minus20

020406080

100120140160180200220240260280

(440)

(511)

(422)(400)

(311)

(220)

Inte

nsity

(au

)

2120579 (deg)

Ca 7

Ca 5

Ca 3

Ca 1

MgF

Figure 3 X-ray diffraction pattern of pure and Ca2+ substitutedMgFe

2O4representing the formation of polycrystalline cubic spinel

phase

minus001 000 001 002 003 004 005 006 007 008838

839

840

841

842

843

844

Number of Ca atoms substituted

Latti

ce p

aram

eter

(A)˚

Figure 4 Variation of lattice parameter ldquo119886rdquo of the compositionMgCa

119909Fe2minus119909

O4(119909 = 00 001 003 005 007) as a function of

concentration ldquo119909rdquo

The case of Mg-ferrite is somewhat exceptional Its struc-ture was originally reported to be inverted that is having thesame number of magnetic atoms on A-sites as on B-sites [36]On the basis of the Neel coupling scheme Mg-ferrite wouldthen be expected to have zero saturation moment Howeverthis was not observed experimentally and the saturationmoment was found to vary within the limits of 1ndash24 Bohrmagnetons depending on the conditions of preparation [37]This discrepancy has been explained on the assumption thatMg-ferrite is incompletely inverted the number of iron atomson B-sites thus exceeds the number on A-sites Smit andWijn[35] reported the magnetic moment per molecule MgFe

2O4

at 0 K as 11 Bohr magnetonsIn the present system the magnetic properties are sen-

sitive to the distribution of Fe3+ ion in A- and B-sites


minus40

minus30

minus20

minus10

0

10

20

30

40minus

2000

0

minus15

000

minus10

000

minus50

00 0

5000

1000

0

1500

0

2000

0

Mag

netiz

atio

n (e

mu

gm)

Applied field (Oersted)

MgFCa 1Ca 3

Ca 5Ca 7

Figure 5 M-H curve showing variation of magnetization (emug)versus applied magnetic field (Oer) for pure and Ca substitutedMgFe

The measurement of bulk saturation magnetization cangive the micromagnetic moment information which canbe related to the distribution of the magnetic ions in theinterstitial sites [7]

According to Neelrsquos theorem of sublattice [31 32] the netmagnetization will be

|119872| =1003816100381610038161003816119872B1003816100381610038161003816 minus1003816100381610038161003816119872A1003816100381610038161003816 (4)

The magnetization in each composition depends on thedistribution of Fe3+ ions among the two sites A and B wherethe Mg2+ and Ca2+ ions are nonmagnetic As the magnesiumferrite is partly inverse in nature so there is a probability ofmigration of a small fraction (119910) of Mg2+ ions to A-sites [31]in this case the cation distribution can be represented as

(Mg2+119910Fe3+1minus119910)A[Mg2+1minus119910

Fe3+1+119910]BO2minus4

(5)

The first and the second bracket indicates tetrahedral(A-site) and octahedral (B-site) sublattice respectively ForMgFe

2O4 the value of ldquo119910rdquo is approximately equal to 01 [35]

The ionic magnetic moment of Mg2+ is zero (nonmagnetic)and the magnetic moment of Fe3+ is 5 The replacement ofFe3+ ion by ldquo119909rdquo Ca2+ ions where Ca2+ ions prefer to occupyA-site gives (1minus119909minus119910) Fe3+ ions on the A-site and (1+119909+119910)Fe3+ ions on the B-site This distribution will take the form

(Ca2+119909Mg2+119910Fe3+1minus119909minus119910)A[Mg2+1minus119909minus119910

Fe3+1+119909+119910]BO2minus4

(6)

This substitution will lead to increasing Fe3+ ions on theB-site and consequently the magnetization of the B-site will

increase and at the same time the magnetization of A-sitewill decrease according to the decrease of Fe3+ ion on A-siteAccordingly the net magnetization will increase in the range119909 le 005 as given in the table Further the magnetizationdecreases with increasing ldquo119909rdquo for 119909 gt 005 This behaviourmay be related to the migration of Ca2+ ions to B-site so thatthe cation distribution of formula (6) was applied to the rangeof 119909 le 005 but for 119909 gt 005 the cation distribution will bemodified to the formula

(Ca2+119909minus119910

Fe3+1+119910minus119909)A[Mg2+1minus119909

Ca2+119910Fe3+1+119909minus119910]BO2minus4

(7)

From this distribution the increase of calcium contentwill prevent the existence of Mg2+ ions on A-site Also thenumber of Fe3+ ionswill decrease onB-site and increase onA-site by the same amount (ie 119910 Fe3+ ions) This replacementwill weaken the net magnetization of the whole lattice [32]

In case of Ca-ion distribution it was reported [19 27 38]that Ca2+ ions strongly prefer to occupy the A-site for lowCa concentration however for high Ca concentration Ca2+ions either are distributed between A- and B-sites [10] orreside at the grain boundaries [20] Carter and Mason [21]report that calcium at higher concentration segregates almostcompletely at the grain boundaries Thus according to theassumed cation distribution (Ca ions occupy the A-sites)increase of the Ca concentration from 119909 = 000 to 119909 = 005leads Fe3+ content in B-site to increase and that in A-siteto decrease Hence the total magnetization (119872 = 119872B minus

119872A) increases For 119909 gt 005 more Fe3+ ions migrate to B-site causing the B-B interaction to increase and hence thecanting angle (120579yk) is established Therefore it is suggestedthat significant canting exists at octahedral B-sites which canbe explained on the basis of three-sublattice model suggestedby Yafet and Kittel [39] It is expected that (120579yk) increaseswith increasing Ca concentration such an increase in (120579yk)leads to a decrease of 119872

119904according to the equation 119872

119904=

119872B Cos 120579yk minus119872A where119872A and119872B are the magnetizationsof A- and B-sites respectively [40] Thus our results supportthe occupation of Ca ions for A-sites at low Ca concentrationOur observations also support the earlier work [41] wherefor higher concentration of nonmagnetic ions119872

119904decreases

with ldquo119909rdquowhich is due to theweakening ofA-B interaction andconsequently stronger B-B interaction

Figure 6 shows the magnetization versus temperaturecurves of pure andCa2+ substitutedMg-ferrite for a field of 50oersted From this figure the value of Curie temperature (119879

119862)

(the temperature at which the value of magnetization reducesto zero) is calculatedThe values of saturation magnetizationcoercivity retentivity and Curie temperature are given inTable 4 It is clear from Table 4 that the value of Curietemperature decreases with increase in Ca2+ ions The Curietemperature of a substituted ferrite will vary as per thevariation in the relative strength of the A-B super exchangeinteractions due to nonmagnetic ion (Ca2+) substitution inA-site Since the present system has only one magnetic ion(Fe3+) the variation of ldquo119879

119862rdquo is determined by the ratio of

iron concentration in A and B sites in substituted ferrite withrespect to that of an unsubstituted ferrite (MgFe

2O4) [7]The

value of Curie temperature ldquo119879119862rdquo for unsubstituted ferrite that


minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)

Figure 6 The saturation magnetization (119872119878) as a function of

temperature for pure and Ca substituted MgFe at a fixed field of 50oersted

isMgFe2O4 is 400∘Cwhich continuously decreases to 328∘C

for Ca 7 substituted Mg-ferrite Initially when the dopingpercentage is small (119909 = 001) very negligible Ca2+ ions gointo the spinel and hence the number of magnetic ions onA-site is comparatively larger Therefore the A-B interactionis comparatively stronger resulting in slight decrease of curietemperature [20] whereas with increased doping percentagefrom 119909 = 001 to 119909 = 007 the number of nonmagneticions (Ca2+) occupying A-site reduces the magnetic momentof A-site [20] thereby making A-B interaction weaker whichcauses reduction in Curie temperature [20 21 28]

4 Conclusion

Structural and magnetic properties of magnesium ferrite(MgFe) and calcium substituted MgFe depend on severalfactors including method of preparation chemical composi-tion and grain size of the particles Pure and Ca substitutedmagnesium ferrite of the form MgCa

119909Fe2minus119909

O4(for 119909 = 000

001 003 005 007) were successfully prepared by solid statereaction technique The X-ray diffraction analysis confirmsthe formation of cubic spinel structure The lattice parameterincreases up to 119909 le 003 and then starts decreasing for 119909 gt003 The EDAX results confirm the presence of the requiredelements in the prepared composition The magnetizationincreases for small Ca concentration that is 119909 le 005 andthen decreases for higher Ca concentration that is 119909 gt005 The replacement of iron by calcium ions leads to cationdistribution as explained in formula (6) and (7) MgFe

2O4

represents the highest Curie temperature which decreaseswith the increase in substitution of nonmagnetic ion (Ca2+)

The presence of Mg2+ and Ca2+ ions on A-sites or on B-sitescauses a decrease in Fe3+A -Fe3+B magnetic interaction therebylowering the Curie temperature

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] A Pradeep P Priyadharsini and G Chandrasekaran ldquoSol- gelroute of synthesis of nanoparticles of MgFe

2O4and XRD FTIR

and VSM studyrdquo Journal of Magnetism and Magnetic Materialsvol 320 no 21 pp 2774ndash2779 2008

[2] U Ozgur Y Alivov and HMorkoc ldquoMicrowave ferrites part 1fundamental propertiesrdquo Journal of Materials Science Materialsin Electronics vol 20 no 9 pp 789ndash834 2009

[3] W V Aulock Handbook of Microwaves Ferrites MaterialsAcademic Press New York NY USA 1965

[4] S K A V Ahamed K Sahib M Suganthi and C PrakashldquoStudy of electrical and magnetic properties in nanosized Ce-Gd doped magnesium ferriterdquo International Journal of Com-puter Applications vol 27 no 5 pp 40ndash45 2011

[5] H Knock and H Dannheim ldquoTemperature dependence of thecation distribution in magnesium ferriterdquo Physica Status Solidi(A) vol 37 pp K135ndashK137 1976

[6] E De Grave C Dauwe A Govaert and J De Sitter ldquoCationdistribution and magnetic exchange interactions in MgFe

2O4

studied by the mossbauer effectrdquo Physica Status Solidi (B) BasicResearch vol 73 no 2 pp 527ndash532 1976

[7] S D Chhaya M P Pandya M C Chhantbar K B Modi G JBaldha and H H Joshi ldquoStudy of substitution limit structuralbulk magnetic and electrical properties of Ca2+ substitutedmagnesium ferriterdquo Journal of Alloys and Compounds vol 377no 1-2 pp 155ndash161 2004

[8] M Pavlovic C Jovalekic A S Nikolic D Manojlovic and NSojic ldquoMechanochemical synthesis of stoichiometric MgFe

2O4

spinelrdquo Journal ofMaterials ScienceMaterials in Electronics vol20 no 8 pp 782ndash787 2009

[9] H H Joshi and R G Kulkarni ldquoSusceptibility magnetizationand Mossbauer studies of the Mg-Zn ferrite systemrdquo Journal ofMaterials Science vol 21 no 6 pp 2138ndash2142 1986

[10] R V Upadhyay and R G Kulkarni ldquoThemagnetic properties oftheMgCd ferrite system byMossbauer spectroscopyrdquoMaterialsResearch Bulletin vol 19 no 5 pp 655ndash661 1984

[11] R A Brand H Georges-Gibert J Hubsch and J A HellerldquoFerrimagnetic to spin glass transition in the mixed spinelMg1+119905

Fe2minus2119905

TitO4 a Mossbauer and DC susceptibility studyrdquo

Journal of Physics F Metal Physics vol 15 no 9 pp 1987ndash20071985

[12] K B Modi H H Joshi and R G Kulkarni ldquoMagnetic andelectrical properties of Al3+-substituted MgFe

2O4rdquo Journal of

Materials Science vol 31 no 5 pp 1311ndash1317 1996[13] G J Baldha R V Upadhyay and R G Kulkarni ldquoOn the

substitution of calcium in cobalt ferriterdquo Journal of MaterialsScience vol 23 no 9 pp 3357ndash3361 1988

[14] A A Sattar H M El-Sayed and W R Agami ldquoPhysicaland magnetic properties of calcium-substituted Li-Zn ferriterdquoJournal of Materials Engineering and Performance vol 16 no 5pp 573ndash577 2007


[15] A Y Lipare P N Vasambekar and A S Vaingankar ldquoAcsusceptibility study of CaCl

2doped copper-zinc ferrite systemrdquo

Bulletin of Materials Science vol 26 no 5 pp 493ndash497 2003[16] C Pasnicu D Condurache and E Luca ldquoInfluence of sub-

stitution and addition of calcium on magnetic proprties ofNi0245

Zn0755

Fe2O4ferriterdquo Physica Status Solidi (A) Applied

Research vol 76 no 1 pp 145ndash150 1983[17] C Liu B Zou A J Rondinone and Z J Zhang ldquoChemical

control of superparamagnetic properties of magnesium andcobalt spinel ferrite nanoparticles through atomic level mag-netic couplingsrdquo Journal of the American Chemical Society vol122 no 26 pp 6263ndash6267 2000

[18] Q-M Wei J-B Li Y-J Chen and Y-S Han ldquoX-ray studyof cation distribution in NiMn

1minus119909Fe2minus119909

O4ferritesrdquo Materials

Characterization vol 47 no 3-4 pp 247ndash252 2001[19] H S C OrsquoNeill and A Navrotsky ldquoCation distributions and

thermodynamic properties of binary spinel solid solutionsrdquoAmerican Mineralogist vol 69 no 7-8 pp 733ndash753 1984

[20] V K Singh N K Khatri and S Lokanathan ldquoMossbauerstudy of ferrite systems Co

119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo

Pramana vol 16 no 4 pp 273ndash280 1981[21] D C Carter and T O Mason ldquoElectrical properties and site

distribution of cations in (Mn119910Co1minus119910

)04Fe26O4rdquo Journal of the

American Ceramic Society vol 71 no 4 pp 213ndash218 1988[22] E D Case J R Smyth and V Monthei ldquoGrain size determi-

nationsrdquo Journal of the American Ceramic Society vol 64 ppC24ndashC25 1981

[23] C Kittel Introduction a La Physique de Lrsquoetat Solide DunodParis France 1958

[24] W B Cross L Afflcck M V Kuznetsov I P Parkin and QA Pankhurst ldquoSelf-propagating high-temperature synthesis offerrites MFe

2O4(M = Mg Ba Co Ni Cu Zn) reactions in an

external magnetic fieldrdquo Journal of Materials Chemistry vol 9no 10 pp 2545ndash2552 1999

[25] C G Whinfrey D W Eckart and A Tauber ldquoPreparation andX-ray diffraction data for some rare earth stannatesrdquo Journal ofthe American Chemical Society vol 82 no 11 pp 2695ndash26971960

[26] D C Khan M Misra and A R Das ldquoStructure and magne-tization studies of Ti-substituted Ni

03Zn07Fe2O4rdquo Journal of

Applied Physics vol 53 no 3 pp 2722ndash2724 1982[27] R V Upadhyay G J Baldha and R G Kulkarni ldquoMossbauer

study of the Ca119909Co1minus119909

Fe2O4systemrdquo Journal of Magnetism and

Magnetic Materials vol 61 no 1-2 pp 109ndash113 1986[28] N Rezlescu and E Rezlescu ldquoInfluence of additives on the

material parameters of Li-Zn ferritesrdquo Physica Status Solidi (A)Applied Research vol 147 no 2 pp 553ndash562 1995

[29] B D Cullity Elements of X-Ray Diffraction Addison-WesleyReading Mass USA 2nd edition 1978

[30] A A Pandit S S More R G Dorik and K M JadhavldquoStructural andmagnetic properties of Co

1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4

ferrite systemrdquo Bulletin of Materials Science vol 26 no 5 pp517ndash521 2003

[31] S A Mazen S F Mansour and H M Zaki ldquoSome physicalandmagnetic properties ofMg-Zn ferriterdquoCrystal Research andTechnology vol 38 no 6 pp 471ndash478 2003

[32] K J Stanlley Oxide Magnetic Materials Clarendon PressOxford UK 1972

[33] J De Sitter A Govaert E De Grave D Chambaere and GRobbrecht ldquoMossbauer study of Ca2+ containing magnetitesrdquoPhysica Status Solidi (A) Applied Research vol 43 no 2 pp 619ndash624 1977

[34] E De Grave J De Sitter and R Vandenberghe ldquoOn the cationdistribution in the spinel system yMg

2TiO4-(1minusy)MgFe

2O4rdquo

Applied Physics vol 7 no 1 pp 77ndash80 1975[35] J Smit and H P J Wijn Ferrites Cleaver-Hume Press London

UK 1959[36] T F W Barth and E Posnjak ldquoSpinel structures with and with-

out variate atom equipointsrdquoZeitschrift fur Kristallographie vol82 pp 325ndash341 1932

[37] C Guillaud ldquoProprieties magnetiques des ferritesrdquo Journal dePhysique et Le Radium vol 12 pp 239ndash248 1951

[38] N Rezlescu and E Rezlescu ldquoEffects of addition of Na2O

Sb2O3 CaO and ZrO

2on the properties of lithium zinc ferriterdquo

Journal of the American Ceramic Society vol 79 no 8 pp 2105ndash2108 1996

[39] Y Yafet and C Kittel ldquoAntiferromagnetic arrangements inferritesrdquo Physical Review vol 87 no 2 pp 290ndash294 1952

[40] S S Suryawanshi V V Deshpande U B Deshmukh S MKabur N D Chaudhari and S R Sawant ldquoXRD analysis andbulk magnetic properties of Al3+ substituted Cu-Cd ferritesrdquoMaterials Chemistry andPhysics vol 59 no 3 pp 199ndash203 1999

[41] S T Alone and K M Jadhav ldquoStructural and magnetic prop-erties of zinc-and aluminum-substituted cobalt ferrite preparedby co-precipitation methodrdquo Pramana vol 70 no 1 pp 173ndash181 2008

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


[17] Thus determination of cation distribution between thetetrahedral and octahedral sites has been a subject of manystudies [18ndash21] Wei et al [18] from the X-ray diffractionstudies proposes that withmanganese ion substitutionMn3+ions predominately occupy the octahedral site whereas Fe3+ion decreases linearly thereby suggesting that Fe3+ is beingreplaced by Mn3+ ion on substitution

In the present paper calcium (Ca) substituted magne-sium ferrite is reported with a view to study the effect ofsubstitution of nonmagnetic ion (Ca2+) on the structuraland magnetic behaviour The free ionic radius of the cationsinvolved is Mg2+ (066 A) Ca2+ (099 A) and Fe3+ (064 A)Therefore it would be interesting to substitute large cationCa2+ (whose radius is near the threshold sim1 A) for Fe3+ inMgFe

2O4

2 Materials and Methods

21 Materials Preparation Pure magnesium ferrite (MgFe)and calcium substituted magnesium ferrite (CaMgFe) withcomposition MgCa

119909Fe2minus119909

O4(119909 = 000 001 003 005 007)

were prepared using the ceramic technique High purityoxides 9999 of CaO MgO and Fe

2O3 were used as

starting materials The oxides of metal ions were mixedtogether according to their molecular weight The mixture ofeach samplewas ground to a very fine powder in agatemortarThe mixed powder was then transferred to electric ball millfor 48 hours The dried powder was pressed into pellets andpresintered at a temperature of 800∘C for 2 hours with aheating rate of 2∘Cmin so that the initial chemical reactionbetween the constituents can take place The presinteredmixture was ground again and pressed into the requiredshapes using hydraulic press under a pressure of 120 kgcm2in order to obtain a high degree of compaction In the finalsintering process the samples were placed in a furnace heatedup to 1200∘C with a heating rate of 4∘Cmin kept for 2hours and then cooled to 900∘C at the rate of 75∘Cmin afterwhich it was cooled to room temperature After sintering thecompactswere polished to remove the surface layers to ensurethat the measured properties correspond to those of the bulkand not the surface layers

22 Characterization In order to confirm the completion ofsolid state reaction as well as analyzing the crystalline phaseand the structural parameters X-ray diffraction patterns ofthe powdered samples were recorded by using a Rigakupowder X-ray diffractometer using Cuk

120572(120582 = 154059 A)

radiation The shape size and distribution of pure andcalcium substituted magnesium ferrite were carried out withthe help of scanning electron microscope (SEM Model LEO440 PC Based DIGITAL SEM) The elemental compositionwas confirmed with the help of energy dispersive X-rayanalysis (EDAX model OXFORD LINK ISIS 300) A fullycomputer controlled vibrating sample magnetometer (VSMEGampG Princeton Applied Research Model 4500) was usedfor magnetization (with a maximum applied field of 15 kOerat room temperature) and Curie temperature measurements

Table 1 Variation of grain size with different composition of Cathat is MgCa

119909Fe2minus119909

O4 (where 119909 = 000 001 003 005 007)

Composition Size (120583m)Pure MgF 399Ca 1 326Ca 3 237Ca 5 167Ca 7 130

3 Results and Discussion

31 Structural Properties Figures 1(a)ndash1(e) show typical scan-ning electron microscopic (SEM) images of MgCa

119909Fe2minus119909

O4

(where 119909 = 000 001 003 005 007) respectively It isclear from these electron micrographs that the materialessentially consists of some irregularly cubic particles in pureMg-ferrite (Figure 1(a)) and agglomeration of these particlesincreases with the increase in Ca2+ ions concentrationThe grain size was calculated using the average interceptline (AIL) method [22] Well-crystallized dense grains ofirregular shapes were observed for these compositions withthe presence of large micropores The grain size of MgFe is399 120583m which decreases with increase in substitution Thecontinuous decrease in grain size with Ca substitution maybe due to the fact that Ca2+ ions (099 A) have large ionicradii than that of Fe3+ (064 A) and therefore show limitedsolubility in spinel lattice and prevent grain growth resultingin decrease in grain size [23] Table 1 shows the values of grainsize with Ca2+ composition in Mg-ferrite

Figures 2(a) and 2(b) show the energy dispersive X-rayanalysis (EDAX) spectrum for 1 and 7 Ca substituted mag-nesium ferrite whereas Table 2 gives quantitative estimationof elements obtained directly from spectrum through itsatomic and weight percentages The results confirmed thepresence of the required elements in the prepared compo-sition with almost all the peaks associated with elementssuch as those of Mg Fe O and Ca thereby suggesting theformation of pure MgFe and CaMgFe

The X-ray diffraction (XRD) studies confirm the forma-tion of polycrystalline cubic spinel phase Figure 3 showsX-ray diffraction pattern indicating (hkl) values for pureand Ca substituted magnesium ferrite The diffraction peakscorresponding to planes (220) (311) (400) (422) (511) and(440) provide a clear evidence for the formation of spinelstructure of the ferrite [24] The ldquo119889rdquo values and intensitiesof the observed diffraction peaks match the crystalline cubicspinel form of the magnesium ferrite (JCPDS Card no 36-0398)

The data on lattice parameter ldquo119886rdquo X-ray density ldquo119863119909rdquo

bulk density ldquo119863119861rdquo and porosity ldquo119875rdquo is summarized in Table 3

The plot of lattice constant ldquo119886rdquo (A) versus calcium content(119909) is depicted in Figure 4 It is found from the figure thatlattice constant initially increases up to119909= 003 and thereafterit decreases with further increase in ldquo119909rdquo This indicates thatthe variation of ldquo119886rdquo with ldquo119909rdquo does not obey Vegardrsquos law[25] This nonlinear behaviour of ldquo119886rdquo with ldquo119909rdquo may be


MgF

(a)

Ca 1

(b)

Ca 3

(c)

Ca 5

(d)

Ca 7

(e)






[29]

119863119909=8119872

1198731198863 (1)

















substituted MgF




(Oer)



000 235 26 152 400001 225 28 153 388003 245 31 200 370005 307 205 138 331007 290 30 196 325



119875 = 1 minus 119863119861119863119909

(2)



respectively




119904) coercivity (119867

119888)



119904) and





CaCa

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

4000

3000

2000

1000

0

5 10

Energy (keV)

(a)

Ca

Ca

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

3000

2000

1000

0

5 10

Energy (keV)

Ca

Ca


Mg

O

Fe

Fe

FeFFFFFFFFFF

(b)






2O4is given by

(Mg01Fe09)A[Mg

09Fe11]B (3)

20 30 40 50 60 70minus20

020406080

100120140160180200220240260280

(440)

(511)

(422)(400)

(311)

(220)

Inte

nsity

(au

)

2120579 (deg)

Ca 7

Ca 5

Ca 3

Ca 1

MgF



phase

minus001 000 001 002 003 004 005 006 007 008838

839

840

841

842

843

844


Latti

ce p

aram

eter

(A)˚


119909Fe2minus119909

O4(119909 = 00 001 003 005 007) as a function of



2O4




minus40

minus30

minus20

minus10

0

10

20

30

40minus

2000

0

minus15

000

minus10

000

minus50

00 0

5000

1000

0

1500

0

2000

0

Mag

netiz

atio

n (e

mu

gm)


MgFCa 1Ca 3

Ca 5Ca 7




|119872| =1003816100381610038161003816119872B1003816100381610038161003816 minus1003816100381610038161003816119872A1003816100381610038161003816 (4)




(5)





Fe3+1+119909+119910]BO2minus4

(6)



(Ca2+119909minus119910



(7)





119904=


119904decreases



119862)




2O4) [7]The



minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)





4 Conclusion


119909Fe2minus119909

O4(for 119909 = 000


2O4





References


2O4and XRD FTIR







2O4




2O4





Fe2minus2119905




2O4rdquo Journal of









Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




MgF

(a)

Ca 1

(b)

Ca 3

(c)

Ca 5

(d)

Ca 7

(e)






[29]

119863119909=8119872

1198731198863 (1)

















substituted MgF




(Oer)



000 235 26 152 400001 225 28 153 388003 245 31 200 370005 307 205 138 331007 290 30 196 325



119875 = 1 minus 119863119861119863119909

(2)



respectively




119904) coercivity (119867

119888)



119904) and





CaCa

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

4000

3000

2000

1000

0

5 10

Energy (keV)

(a)

Ca

Ca

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

3000

2000

1000

0

5 10

Energy (keV)

Ca

Ca


Mg

O

Fe

Fe

FeFFFFFFFFFF

(b)






2O4is given by

(Mg01Fe09)A[Mg

09Fe11]B (3)

20 30 40 50 60 70minus20

020406080

100120140160180200220240260280

(440)

(511)

(422)(400)

(311)

(220)

Inte

nsity

(au

)

2120579 (deg)

Ca 7

Ca 5

Ca 3

Ca 1

MgF



phase

minus001 000 001 002 003 004 005 006 007 008838

839

840

841

842

843

844


Latti

ce p

aram

eter

(A)˚


119909Fe2minus119909

O4(119909 = 00 001 003 005 007) as a function of



2O4




minus40

minus30

minus20

minus10

0

10

20

30

40minus

2000

0

minus15

000

minus10

000

minus50

00 0

5000

1000

0

1500

0

2000

0

Mag

netiz

atio

n (e

mu

gm)


MgFCa 1Ca 3

Ca 5Ca 7




|119872| =1003816100381610038161003816119872B1003816100381610038161003816 minus1003816100381610038161003816119872A1003816100381610038161003816 (4)




(5)





Fe3+1+119909+119910]BO2minus4

(6)



(Ca2+119909minus119910



(7)





119904=


119904decreases



119862)




2O4) [7]The



minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)





4 Conclusion


119909Fe2minus119909

O4(for 119909 = 000


2O4





References


2O4and XRD FTIR







2O4




2O4





Fe2minus2119905




2O4rdquo Journal of









Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials


















substituted MgF




(Oer)



000 235 26 152 400001 225 28 153 388003 245 31 200 370005 307 205 138 331007 290 30 196 325



119875 = 1 minus 119863119861119863119909

(2)



respectively




119904) coercivity (119867

119888)



119904) and





CaCa

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

4000

3000

2000

1000

0

5 10

Energy (keV)

(a)

Ca

Ca

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

3000

2000

1000

0

5 10

Energy (keV)

Ca

Ca


Mg

O

Fe

Fe

FeFFFFFFFFFF

(b)






2O4is given by

(Mg01Fe09)A[Mg

09Fe11]B (3)

20 30 40 50 60 70minus20

020406080

100120140160180200220240260280

(440)

(511)

(422)(400)

(311)

(220)

Inte

nsity

(au

)

2120579 (deg)

Ca 7

Ca 5

Ca 3

Ca 1

MgF



phase

minus001 000 001 002 003 004 005 006 007 008838

839

840

841

842

843

844


Latti

ce p

aram

eter

(A)˚


119909Fe2minus119909

O4(119909 = 00 001 003 005 007) as a function of



2O4




minus40

minus30

minus20

minus10

0

10

20

30

40minus

2000

0

minus15

000

minus10

000

minus50

00 0

5000

1000

0

1500

0

2000

0

Mag

netiz

atio

n (e

mu

gm)


MgFCa 1Ca 3

Ca 5Ca 7




|119872| =1003816100381610038161003816119872B1003816100381610038161003816 minus1003816100381610038161003816119872A1003816100381610038161003816 (4)




(5)





Fe3+1+119909+119910]BO2minus4

(6)



(Ca2+119909minus119910



(7)





119904=


119904decreases



119862)




2O4) [7]The



minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)





4 Conclusion


119909Fe2minus119909

O4(for 119909 = 000


2O4





References


2O4and XRD FTIR







2O4




2O4





Fe2minus2119905




2O4rdquo Journal of









Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




CaCa

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

4000

3000

2000

1000

0

5 10

Energy (keV)

(a)

Ca

Ca

Ca

Mg

O

Fe

Fe

Fe

Cou

nts

3000

2000

1000

0

5 10

Energy (keV)

Ca

Ca


Mg

O

Fe

Fe

FeFFFFFFFFFF

(b)






2O4is given by

(Mg01Fe09)A[Mg

09Fe11]B (3)

20 30 40 50 60 70minus20

020406080

100120140160180200220240260280

(440)

(511)

(422)(400)

(311)

(220)

Inte

nsity

(au

)

2120579 (deg)

Ca 7

Ca 5

Ca 3

Ca 1

MgF



phase

minus001 000 001 002 003 004 005 006 007 008838

839

840

841

842

843

844


Latti

ce p

aram

eter

(A)˚


119909Fe2minus119909

O4(119909 = 00 001 003 005 007) as a function of



2O4




minus40

minus30

minus20

minus10

0

10

20

30

40minus

2000

0

minus15

000

minus10

000

minus50

00 0

5000

1000

0

1500

0

2000

0

Mag

netiz

atio

n (e

mu

gm)


MgFCa 1Ca 3

Ca 5Ca 7




|119872| =1003816100381610038161003816119872B1003816100381610038161003816 minus1003816100381610038161003816119872A1003816100381610038161003816 (4)




(5)





Fe3+1+119909+119910]BO2minus4

(6)



(Ca2+119909minus119910



(7)





119904=


119904decreases



119862)




2O4) [7]The



minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)





4 Conclusion


119909Fe2minus119909

O4(for 119909 = 000


2O4





References


2O4and XRD FTIR







2O4




2O4





Fe2minus2119905




2O4rdquo Journal of









Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




minus40

minus30

minus20

minus10

0

10

20

30

40minus

2000

0

minus15

000

minus10

000

minus50

00 0

5000

1000

0

1500

0

2000

0

Mag

netiz

atio

n (e

mu

gm)


MgFCa 1Ca 3

Ca 5Ca 7




|119872| =1003816100381610038161003816119872B1003816100381610038161003816 minus1003816100381610038161003816119872A1003816100381610038161003816 (4)




(5)





Fe3+1+119909+119910]BO2minus4

(6)



(Ca2+119909minus119910



(7)





119904=


119904decreases



119862)




2O4) [7]The



minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)





4 Conclusion


119909Fe2minus119909

O4(for 119909 = 000


2O4





References


2O4and XRD FTIR







2O4




2O4





Fe2minus2119905




2O4rdquo Journal of









Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




minus05

05

15

25

35

45

55

0 50 100 150 200 250 300 350 400 450 500 550

Mag

netiz

atio

n (e

mu

gm)

PureCa 1Ca 3

Ca 5Ca 7

Temperature (∘C)





4 Conclusion


119909Fe2minus119909

O4(for 119909 = 000


2O4





References


2O4and XRD FTIR







2O4




2O4





Fe2minus2119905




2O4rdquo Journal of









Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials








Zn0755










119909Mn1minus119909

Fe2O4and Ni

119909Mn1minus119909

Fe2O4rdquo




















1+119910Sn119910Fe2minus2119910minus119909

Cr119909O4






2TiO4-(1minusy)MgFe

2O4rdquo






Sb2O3 CaO and ZrO













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



Documents

Research Article Preparation, and Structural and Magnetic …downloads.hindawi.com/archive/2014/184340.pdf · 2019-07-31 · Research Article Preparation, and Structural and Magnetic