Mössbauer investigation of Mn2Sb doped with Fe and Cr

The alloy systems Mn_2?xFe_xSb and Mn_1.98?xCr_xFe_0.02Sb have been investigated by Mössbauer spectroscopy of ⁵⁷Fe in the region x? 0.2.In Mn_2?xFe_xSb the spinflop transition known to exist in pure Mn₂Sb at T_t = 240 K is observed. At T_t the magnetic hyperfine field H changes from -50 to -80 kOe and the electric quadrupole interaction QS from positive to negative with increasing T. The value of ΔH at T_t can be understood in terms of dipolar contributions to H. Fe is deduced to occupy the Mn_I sites in the lattice.In Mn_1.98?xCr_xFe_0.02Sb the transition from the ferrimagnetic to the antiferromagnetic state is observed. In the antiferromagneti c state we find | H| ≈ 15 kOe.