  We report the observation of large magnetocaloric effect near room
temperature in antipervoskite SnCMn3. The maximal magnetic entropy change at
the first-order ferrimagnetic-paramagnetic transition temperature (TC 279 K) is
about 80.69mJ/cm3 K and 133mJ/cm3 K under the magnetic field of 20 kOe and 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 TC. Through the
measurements of Seebeck coefficient and normal Hall effect, the title system is
found to undergo a reconstruction of electronic structure at TC. 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.
