COHERENT FERROMAGNETIC PRECIPITATE AND ANOMALIES IN THE HEAT-CONDUCTION AND THERMOPOWER OF MN2-XCRXSB SINGLE-CRYSTALS

The heat diffusivity D, the Electrical resistivity rho and the thermoe lectric power S of tetragonal Mn2-x CrxSb single crystals with 0.02 < x < 0.12 have been measured in the temperature range of 90 K < T < 350 K and along different crystal axes. The heat conductivity kappa and s igma = 1/rho are anisotropic along the crystal axes a, c with a ratio of 2:1. kappa(T), rho(T) and S(T) show anomalies at the spin reorienta tion temperature Tn, of the matrix (M) Mn2-xCrxSb, but also at that of the coherent ferromagnetic precipitate (P) Mn1.037Cr0.11Sb, T-Rp whic h is assigned to variations in the spin dependent scattering at the M/ P interfaces via changes in the relative orientation of the magnetizat ion vectors of matrix and precipitate (spin valve effect).