Phase separation and effect of strain on magnetic properties of Mn sub(3)Ga sub(1-x)Sn sub(x)C

Abstract

While the unit cell volume of compounds belonging to the Mn sub(3)Ga sub(1-x)Sn sub(x)C (0 less than or equal to x less than or equal to 1) series shows a conformity with Vegard’s law, their magnetic and magnetocaloric properties behave differently from those of parent compounds Mn sub(3)GaC and Mn sub(3)SnC. A correlation between the observed magnetic properties and underlying magnetic and local structure suggests that replacing Ga atoms by larger atoms of Sn results in the formation of Ga-rich and Sn-rich clusters. As a result, even though the long range structure appears to be cubic, Mn atoms find themselves in two different local environments. The packing of these two different local structures into a single global structure induces tensile/compressive strains on the Mn sub(6)C functional unit and is responsible for the observed magnetic properties across the entire solid solution range.