Thermodynamic and transport properties of single-crystal Yb{sub 14}MnSb{sub 11}

Description/Abstract

Relatively large (up to 250 mg) single crystals of the intermetallic compound Yb{sub 14}MnSb{sub 11} have been prepared by a flux-growth technique. The results of thermodynamic and transport measurements of these samples are presented. The compound orders ferromagnetically at approximately T{sub C}=53{plus_minus}1K, with a magnetization consistent with the assignment Mn{sup 3+} (3d{sup 4}) and Yb{sup 2+} (4f{sup 14}). The Mn moments are local in nature, with the full effective and saturated moment of the Hund{close_quote}s rule spin-only ground state. The electrical resistivity has a metallic temperature dependence, with only a modest anisotropy. Room-temperature values of the resistivity are relatively high for an intermetallic compound: 1630{plus_minus}160 {mu}{Omega}cm and 1250{plus_minus}130 {mu}{Omega}cm for currents flowing approximately parallel and perpendicular to the {ital c} axis, respectively. There is a distinct loss of spin-disorder scattering in the resistivity at T{sub C}. From the heat capacity, a rough estimation of the magnetic entropy gives {Delta}S{sub M}{approx}12.1 J/mol K, the value in reasonable agreement with the expected {Delta}S{sub M}{approx}R ln 5 from the assignment of these moments. All of these data are consistent with a picture of Mn{sup 3+} local moments being coupled via conduction electrons. To this end, Yb{sub 14}MnSb{sub 11} appears to be analogous to local-moment rare-earth intermetallic compounds, and may point the way toward a class of 3d Kondo lattice compounds. {copyright} {ital 1999} {ital The American Physical Society}