Magnetocaloric as a sensitive tool to study magnetic phase in Ca4Mn3O10-δ

We report here magnetic properties of non-stoichiometric Ca4Mn3O10-δ. We have measured magnetization, electrical resistance, magnetoresistance, specific heat and thermo remanent magnetization (TRM) relaxation measurements. We find that at temperatures above 75 K the electrical transport can be explained in terms of activated hopping of magnetic polarons. These polarons are formed due to oxygen vacancy inducing Mn3+ sites. Below 50 K the polarons begins to strongly localize causing loss of moment and the electrical transport is governed by variable range hopping (VRH) conduction. The system shows glassy spin relaxation below 50 K, which presumably evolves into cluster spin glass at 12 K due to short range ordering of the canted moments. All these aspect could be well correlated with characteristics signature from magnetocaloric effect indicating magnetocaloric is a sensitive tool to study magnetic phase.