Large magnetic entropy change near room temperature in antiperovskite SnCMn3

We report the observation of a large magnetocaloric effect near room temperature in the antiperovskite SnCMn3. The maximal magnetic entropy change at the first-order ferrimagnetic-paramagnetic transition temperature ($T_{{\rm C}}$ ~ 279 K) is about 80.69 mJ/cm3 K and 133 mJ/cm3 K under a magnetic field of 20 kOe and of 48 kOe, respectively. These values are close to those of typical magnetocaloric materials. The large magnetocaloric effect is associated with the sharp change of lattice, resistivity and magnetization in the vicinity of $T_{{\rm C}}$. Through the measurements of the Seebeck coefficient and normal Hall effect, the title system is found to undergo a reconstruction of the electronic structure at $T_{{\rm C}}$. Considering its low-cost and innocuous raw materials, Mn-based antiperovskite compounds are suggested to be appropriate for pursuing new materials with larger magnetocaloric effect.