Magnetic phase transition in Mn0.5Te0.5−xSbx

The magnetic phase transition in the (NiAs-type) system Mn0.5Te0.5−xSbx was investigated by electrical resistivity and x-ray powder diffraction techniques. Crystallographically, the lattice parameter (a) was found to decrease smoothly with x, while (c) behaved in a steplike manner with the changeover taking place at 0.2 1.63) which typifies the metallic nature (at x>0.3) in nickel arsenides. On the other hand, the shapes of the electrical resistivity curves exhibited a gradual evolution with increasing x values, confirming the proposed phase transition. A plot of resistivity minima versus x showed a clear inversion in the range 0.2