Effect of Crystal Size on the Magnetic Entropy Change in CoCr<sub>2</sub>O<sub>4</sub>

The size effect of magnetocaloric effect (MCE) in CoCr2O4 has been investigated by comparing two samples with different crystal sizes. One is bulk CoCr2O4 sample (referred as A), and the other is a nanocrystalline CoCr2O4 sample (referred as B). It has been found that crystal size dramatically affects the magnetic properties and MCE for CoCr2O4, and that the nanocrystalline material is more favorable for application than the bulk material. The above results are explained in terms of the effect of small size and its distribution for sample B on the intrinsic magnetic properties and magnetic entropy change.