Magnetic and transport properties of Te doped Yb sub(14)MnSb sub(11)

A series of single crystal samples, Yb sub(14)MnSb sub(11-x)Te sub(x) (x less than or equal to 0.2), were investigated via Sn flux. The element distributions were mapped using an electron microprobe, which demonstrated inhomogeneity and limited solubility of Te in the crystals. The magnetic properti...

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Bibliographic Details
Published in:Journal of materials chemistry 2012-07, Vol.22 (29), p.14378-14384
Main Authors: Yi, Tanghong, Abdusalyamova, M N, Makhmudov, F, Kauzlarich, Susan M
Format: Article
Language:English
Subjects:
Carrier density
Crystals
Electron probes
Figure of merit
Order disorder
Reduction
Thermal conductivity
Thermoelectricity
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Summary:A series of single crystal samples, Yb sub(14)MnSb sub(11-x)Te sub(x) (x less than or equal to 0.2), were investigated via Sn flux. The element distributions were mapped using an electron microprobe, which demonstrated inhomogeneity and limited solubility of Te in the crystals. The magnetic properties of two crystals of compositions Yb sub(13.80(2))Mn sub(1.03(1))Sb sub(11.11(4))Te sub(0.06(3)) and Yb sub(13.82(3))Mn sub(1.02(1))Sb sub(11.02(8))Te sub(0.14(6)) were investigated. Increasing amounts of Te increase the saturation moment of Yb sub(14)MnSb sub(11-x)Te sub(x), and slightly lower the ordering temperature T sub(C) by about 1 K. This is attributed to the filling of the hole in Yb sub(14)MnSb sub(11) and the reduction of the screening of the Mn super(2+) d super(5) electrons, resulting in a higher effective moment. Hot-pressed, fully dense pellets of Yb sub(13.72(3))Mn sub(1.08(1))Sb sub(11.13(6))Te sub(0.07(5)), Yb sub(13.76(5))Mn sub(1.11(1))Sb sub(10.96(8))Te sub(0.16(8)), and Yb sub(13.76(4))Mn sub(1.10(2))Sb sub(10.95(9))Te sub(0.19(7)) were prepared for thermoelectric property measurements. Both Seebeck coefficient and electrical resistivity increase with increasing amount of Te as a result of decreasing carrier concentration. Increasing amounts of YbTe with increasing x could be identified in the electron microprobe. The total thermal conductivity was approximately the same for all compositions, similar to that of Yb sub(14)MnSb sub(11). The figure of merit zT reaches a maximum of 1.11 for x= 0.07 at 1240 K, which is approximately 12% higher than the parent compound, Yb sub(14)MnSb sub(11).
ISSN:0959-9428
1364-5501
DOI:10.1039/c2jm32089d