Magnetic behaviour for the MnIn2(1-z)Ga2zSe4 alloys

Polycrystalline samples of MnIn2(1-z)Ga2zSe4 system were prepared by the me lt and anneal technique. Low-field measurements of magnetic susceptibility chi were made as a function of temperature in the range 2 to 300 K. Values of T-N, the Neel temperature, were obtained from the cusp in the chi versus T curves. The 1/chi versus T curves indicated that for 0 < z < 0.30, the M n is randomly distributed over the cation sublattice and the compound MnIn2 Se4 (z = 0) was found to be spin-glass, with T-g = 2.75 K and theta = -94 K . The samples in the composition range 0.75 < z < 1.0 all showed an ordered distribution of Mn2+ ions on the cation sublattice and were antiferromagne tic showing ideal Curie-Weiss behaviour, T-N = 8 K and theta = -24 K.