Thermodynamic and transport properties of single-crystalYb14MnSb11

Abstract

Relatively large (up to 250 mg) single crystals of the intermetallic compound ${\mathrm{Yb}}_{14}{\mathrm{MnSb}}_{11}$ 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 ${T}_{C}=53\ifmmode\pm\else\textpm\fi{}1\mathrm{K},$ with a magnetization consistent with the assignment ${\mathrm{Mn}}^{3+}$ ${(3d}^{4})$ and ${\mathrm{Yb}}^{2+}$ ${(4f}^{14}).$ 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: $1630\ifmmode\pm\else\textpm\fi{}160\ensuremath{\mu}\ensuremath{\Omega}\mathrm{cm}$ and $1250\ifmmode\pm\else\textpm\fi{}130\ensuremath{\mu}\ensuremath{\Omega}\mathrm{cm}$ 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 ${T}_{C}.$ From the heat capacity, a rough estimation of the magnetic entropy gives $\ensuremath{\Delta}{S}_{M}\ensuremath{\approx}12.1\mathrm{J}/\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{}\mathrm{K},$ the value in reasonable agreement with the expected $\ensuremath{\Delta}{S}_{M}\ensuremath{\approx}R\mathrm{ln}5$ from the assignment of these moments. All of these data are consistent with a picture of ${\mathrm{Mn}}^{3+}$ local moments being coupled via conduction electrons. To this end, ${\mathrm{Yb}}_{14}{\mathrm{MnSb}}_{11}$ appears to be analogous to local-moment rare-earth intermetallic compounds, and may point the way toward a class of $3d$ Kondo lattice compounds.