Yb14−xTmxMnSb11 (0

Abstract

The compounds, Yb14−xTmxMnSb11 (0<x<0.5), were synthesized as single crystals via Sn flux. The maximum amount of Tm was determined from wavelength dispersive microprobe analysis to be x=0.45 (1). Single crystal data are consistent with the Ca14AlSb11 structure type and one formula unit can be described as consisting of 14 Yb2+ cations, MnSb4 tetrahedron, Sb3 linear anion and 4 Sb3- anions. The site occupancy of the Tm atom was not determined because of the small amount and small difference in scattering between Tm and Yb. The difference in bond lengths or angles between the solid solution and pristine Yb14MnSb11 is less than 1%. The magnetic susceptibility of samples prepared by Sn flux with the nominal composition of Yb14−xTmxMnSb11 (x=0.1, 0.2, 0.3, and 0.4), show that these phases are ferromagnetic at low temperature with the TC decreasing from 56 to 39K with increasing x. Magnetic saturation for the x=0.4 composition at 5K is consistent with Tm being present as Tm3+ and a negative magnetoresistance ratio (MR=[(ρ(H)−ρ(0))/ρ(H)]×100%) of 18% at 3T is observed.