Absence of first order magnetic transition, a curious case of Mn3InC

Abstract

The volume expanding magnetostructural transition in Mn3GaC and Mn3SnC has been identified to be due to distortion of Mn6Coctahedra. Despite a similar lattice volume as Mn3SnC and similar valence electron contribution to density of states as inMn3GaC, Mn3InC does not undergo afirst order magnetostructural transformation like the Ga and Sn antiperovskite counter-parts. A systematic investigation of its structure and magnetic properties using probes like x-ray diffraction, magnetization mea-surements, neutron diffraction, and extended x-ray absorptionfine structure reveals that though the octahedra are distortedresulting in long and short Mn–Mn bonds and different magnetic moments on Mn atoms, the interaction between them remainsferromagnetic. This has been attributed to the strain on the Mn6C octahedra produced due to a relatively larger size of In atomscompared to Sn and Ga. The size of In atoms constricts the deformation of Mn6C octahedra giving rise to Mn–Mn distances thatfavor only ferromagnetic interactions in the compound.