Thermodynamic and transport properties of single-crystal Yb14MnSb11

Relatively large (up to 250 mg) single crystals of the intermetallic compound Yb14MnSb11 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-C = 53 +/- 1 K, with a magnetization consistent with the assignment Mn3+ (3d(4)) and Yb2+ (4f(14)). The Mn moments are local in nature, with the full effective and saturated moment of the Hund'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 +/- 160 mu Omega cm and 1250 +/- 130 mu Omega cm for currents flowing approximately parallel and perpendicular to the c axis, respectively. There is a distinct loss of spin-disorder scattering in the resistivity at Tc. From the heat capacity, a rough estimation of the magnetic entropy gives Delta S(M)approximate to 12.1 J/mol K, the value in reasonable agreement with the expected Delta S(M)approximate to R In 5 from the assignment of these moments. All of these data are consistent with a picture of Mn3+ local moments being coupled via conduction electrons. To this end, Yb14MnSb11 appears to be analogous to local-moment rare-earth intermetallic compounds, and may point the way toward a class of 3d Kondo lattice compounds. [S0163-1829(99)02021-4].