The thermoelectric power of some magnetically ordered transition metal pnictides

The thermoelectric power (TEP) S of MnAs1-xPx (0 < x < 0.17) and Mn2-yCrySb (0 < y < 0.20) single crystals has been measured in the temperature range 77 K < T < 350 K and for various crystal orientations. For both the mono- and bipnictides, below the magnetic ordering temperatures T-C or T-N, the magnon contribution is dominant. In general, the magnetic order-order transitions can be detected in S(T) and values of the Fermi energy are obtained from the diffusion thermopower contribution S-d, once it is separated: for example E-F (x = 0.17) = 3.85 eV, E-F (y = 0.04) = 3.15 eV.