Magnetic and transport properties of Te doped Yb14MnSb11

作者：Yi Tanghong; Abdusalyamova M N; Makhmudov F; Kauzlarich Susan M^*

来源：Journal of Materials Chemistry, 2012, 22(29): 14378-14384.

DOI：10.1039/c2jm32089d

A series of single crystal samples, Yb14MnSb11-xTex (x < 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 Yb13.80( 2)Mn1.03( 1)Sb11.11( 4)Te0.06( 3) and Yb13.82( 3)Mn1.02( 1)Sb11.02( 8)Te0.14( 6) were investigated. Increasing amounts of Te increase the saturation moment of Yb14MnSb11-xTex, and slightly lower the ordering temperature T-C by about 1 K. This is attributed to the filling of the hole in Yb14MnSb11 and the reduction of the screening of the Mn2+ d(5) electrons, resulting in a higher effective moment. Hot-pressed, fully dense pellets of Yb13.72( 3)Mn1.08( 1)Sb11.13( 6)Te0.07( 5), Yb13.76( 5)Mn1.11( 1)Sb10.96( 8)Te0.16( 8), and Yb13.76( 4)Mn1.10( 2)Sb10.95( 9)Te0.19( 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 Yb14MnSb11. 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, Yb14MnSb11.

• 出版日期2012