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Kristin Kendrick, Melissa Menard, Julia Y. Chan
The focus of our research is the search for interesting physical properties through single crystal growth and characterization. Ternary intermetallic compounds Ce:T:In (T = transition metal) have been shown to exhibit exotic properties such as: superconductivity, large magnetocaloric effect, large thermoelectric effect. Many intermetallic phases with martensitic transformations exhibit a large magnetocaloric effect. Ce(T,In)12 has been characterized via single crystal X-ray diffraction but the magnetocaloric and the thermoelectric properties of the compound has not been studied. We have grown via the flux-growth method and characterized via single crystal X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDXS) Ce(T,In)12 (T = Cu, Ag). Future work will focus on single crystal growth of CeT2In (T= Cu, Ag) phases and physical property measurements of both Ce(T,In)12 (T = Cu, Ag) and CeT2In (T= Cu, Ag).
Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803
Interatomic Distances
Ce(Cu,In)12 Ce(Ag,In)12
Ce-environment
Ce-In x 4 3.1705(8) Ce-In x 4 3.3607(8)
Ce-M x 8 3.258(10) Ce-M x 8 3.5314(7)
Ce-Cu x 8 3.5481(2) Ce-Ag x 8 3.7215(2)
M-environment
M-M x 2 2.7026(19) M-M x 2 2.8861(2)
M-Cu x 4 2.7176(3) M-Ag x 4 2.8481(2)
M-In x 2 2.9992(8) M-In x 2 3.1669(3)
Cu-environment Ag-environment
Cu-M x 4 2.7176(16) Ag-M x 4 2.8481(2)
Cu-Cu x 2 2.7220(1) Ag-Ag x 2 2.8820(3)
Cu-In x 4 2.8194(6) Ag-In x 4 2.9726(2)
M = Cu 50(1) % + In 49(1) % M = Ag 33(1) % + In 67(1) %
EDXS (energy-dispersive X-ray spectroscopy)
sample Ce Ag In sample Ce Cu In
mm86 1 4.5(5) 6.1(4) mm94 1 4.0(8) 6.9(4)
mm92 1 5.1(5) 5.3(7) kk2 1 6.1(7) 6.2(8) K. K. acknowledges Melissa Menard for her mentoring and guidance, Dr. Julia Chan for her support in the completion of this project, OSI REU
and NSF for financial support. M.C.M. would like to acknowledge Michael Kangas for useful discussions and NSF DMR-0756281.
Atomic Positions Ce(Cu,In)12
Atom x y z Ueq
Ce 0 0 0 0.0038(5)
M 0 0.7938(2) 0.5 0.0149(6)
Cu 0 0.5 0.25 0.0083(5)
In 0.34209(11) 0 0 0.0102(5)
M = 50(1) % Cu + 49(1) % In
Ce(Ag,In)12
Atom x y z Ueq
Ce 0 0 0 0.0192(4)
M 0 0.21028(12) 0.5 0.0319(4)
Ag 0 0.5 0.25 0.0237(4)
In 0.65371(8) 0 0 0.0239(4)
M = 33(1) % Ag + 67(1) % In
Ce : Ag : In 2 : 10 : 20
mm86 mm92
300˚C
1000 ˚C/ 12 hrs
200 (150 )˚C/hr
650˚C 4 (2)˚C/hr
500˚C 3 days 5 days
500˚C 5 days
Ce : Cu : In 2 : 10 : 20
mm94 kk2
300˚C
1000˚C/ 12 hrs
2˚C/hr
150 (200 )˚C/hr
5 days 650˚C
Flux
Transition Metal
Rare Earth Metal
Cu (2/m)
M (mm)
In (mm)
Ce (4/mmm)
Ag (2/m)
M (mm) In (mm)
*M = Cu + In *M = Ag + In
Ce
In
M
Cu
Ce
Cu (or Ag)
In In
M
Cu (or Ag)
Cu(or Ag) M
CeCu6.05In5.95 Tetragonal I 4/mmm a = 9.2680(7) c = 5.4439(6)
CeAg5.32In6.68 Tetragonal I 4/mmm a = 9.7050(8) c = 5.7640(6)
Superconductivity
http://news.cnet.com/8301-11128_3-10285552-54.html.
http://www.hydrogen-fc.com/wp-content/uploads/2008/03/magnetic_levitation.jpg http://www.chinatrainee.com/images/maglev-train.jpg
http://www.sciencebuddies.org/science-fair-projects/project_ideas /Phys_img093.jpg`
Thermoelectric Effect
http://www.columbia.edu/~xzp1/photos/solarpower.jpg http://www.nano.lth.se/data/nanometer/files/image/TE_car_harvesting.jpg
Magnetocaloric Effect
http://newenergyandfuel.com/
http://thebsreport.files.wordpress.com/2009/05/refrigerator.jpg http://upload.wikimedia.org/wikipedia/en/thumb/c/cb/MCE.gif/256px-MCE.gif
20.0 25.0 30.0 35.0 40.0 45.0 50.0 2θ
Intensity
2 2
0 3 1
0
0 0
2 3
0 1
0 2
2
2 3
1 0
4 0
3 3
0
2 2
2
1 4
1
4 2
0
1 3
2
Intensity
0 0
2 3
0 1
0 2
2
2 3
1 0
4 0
3 3
0 2
2 2
1
4 1
2
4 0
3 1
2
1 5
0
5 0
1
1 2
1
1 3
0
20.0 25.0 30.0 35.0 40.0 45.0 50.0
2θ
Ce(Cu,In)12
Ce(Ag,In)12
x
yz