Dynamics of non-ergodic ferromagnetic/antiferromagnetic ordering and magnetocalorics in antiperovskite Mn3SnC

We investigated the time dependence of the magnetic configuration at the mixed magnetic magnetostructural transition in Mn3SnC. The non-ergodic nature of the transition involves the stabilization of a final magnetic configuration that involves additional AF ordering which is not present when the transition is initiated and develops only in time. We show the presence of the non-ergodicity over a time scale of about 1 hour by field and time-dependent magnetization studies. Two charac- teristic times related to the transition are observed. We also study the equilibrium thermodynamics under ergodic conditions by heat capacity studies and determine the entropy-change and the adiabatic temperature-change around the transition. We find agreement between the indirect and direct methods in determining the adiabatic temperature change and discuss the influence of non-ergodic properties on the magnetocaloric effects.