Magnetic and transport properties of Te doped Yb14MnSb11

Abstract

A series of single crystal samples, Yb 14 MnSb 11Àx Te x (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 Yb 13.80(2) Mn 1.03(1) Sb 11.11(4) Te 0.06(3) and Yb 13.82(3) Mn 1.02(1) Sb 11.02(8) Te 0.14(6) were investigated. Increasing amounts of Te increase the saturation moment of Yb 14 MnSb 11Àx Te x , and slightly lower the ordering temperature T C by about 1 K. This is attributed to the filling of the hole in Yb 14 MnSb 11 and the reduction of the screening of the Mn 2+ d 5 electrons, resulting in a higher effective moment. Hotpressed, fully dense pellets of Yb 13.72(3) Mn 1.08(1) Sb 11.13(6) Te 0.07(5) , Yb 13.76(5) Mn 1.11(1) Sb 10.96(8) Te 0.16(8) , and Yb 13.76(4) Mn 1.10(2) Sb 10.95(9) Te 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 14 MnSb 11 . The figure of merit zT reaches a maximum of 1.11 for x ¼ 0.07 at 1240 K, which is approximately 12% higher than the parent compound, Yb 14 MnSb 11 .

Magnetic remanence in Yb14−RE MnSb11 (RE=Tb, Dy, Ho) single crystals

“…Solid solutions of Yb 14 MnSb 11 have been recently prepared in order to increase the thermoelectric figure of merit of this p-type high temperature material [7]. Solid solutions of La [9,10], Ce [11], Tm [12,13], and Lu [14] substitution for Yb, Al [15] and Zn [16] for Mn, and Ge [17] and Te [18] for Sb have been reported with an emphasis on controlling carrier concentration for thermoelectrics, but these new solid solutions are also of interest as new magnetic materials [11]. However, in many cases, the magnetization has not been reported since the emphasis of the research has been on thermoelectric properties.…”

Optimization of Ca14MgSb11 through Chemical Substitutions on Sb Sites: Optimizing Seebeck Coefficient and Resistivity Simultaneously

“…The smaller resistivity and lower Seebeck coefficient of Yb14MnSb11 samples synthesized as crystals are also consistent with the above statements. Further studies show that 1% Te or Ge substitutions on Sb site can significantly alter the thermoelectric properties [33,34]. The synthesis and thermoelectric properties of Ca 14 MgSb 11−x Sn x are systematically investigated.…”

Cationic Site-Preference in the Yb14-xCaxAlSb11 (4.81 ≤ x ≤ 10.57) Series: Theoretical and Experimental Studies

“…Among several Zintl phase compounds considered as potential thermoelectric materials, Yb 14 MnSb 11 is one of the best p -type TE material for the high temperature applications [10]. In order to improve its figure of merit zT value even further, various cationic or anionic element substitutions have been attempted, respectively, to lower the lattice thermal conductivity or to optimize the carrier concentration [11,12,13,14,15]. …”