Kristin Kendrick, Melissa Menard, Julia Y. Chan€¦ · Kristin Kendrick, Melissa Menard, Julia Y....

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