Co-existence of ferromagnetic and antiferromagnetic interactions in Mn(3)Ga(1-x)Sn(x)C

Abstract

The magnetic properties of the Mn3Ga(1-x)SnxC, 0 less than equal to x less than equalt to 1 antiperovskite compounds have been investigated in detail. Though all compounds of this series crystallize in a cubic structure, the Ga rich (x less than equal to 0.2) compounds transform, via a first order transformation, to an antiferromagnetic ground state and the Sn rich (x more than equal to 0.8) compounds exhibit dominant ferromagnetic interactions at low temperature. In the intermediate range (0.4 less than equal to x less than equal to 0.7) co-existence of ferromagnetic and antiferromagnetic interactions can be seen. The results have been explained to be due to growth of ferromagnetic sub-lattice at the expense of antiferromagnetic sublattice with increasing Sn concentration in Mn3Ga(1-x)SnxC. This growth occurs to a point where the first-order transition is altered from a ferromagnetic - antiferromagnetic type in Ga rich compounds to a paramagnetic - ferrimagnetic type in Mn3SnC.