Influence of spin reorientation on magnetocaloric effect in NdAl2:: A microscopic model

We report a theoretical investigation about the influence of the spin reorientation from easy magnetic direction < 001 > to the applied magnetic field direction < 111 > on the magnetocaloric properties of NdAl2. This compound was fully investigated using a model Hamiltonian which includes the Zeeman-exchange interactions and the crystalline electrical field, which are responsible for the magnetic anisotropy. All theoretical results were obtained using the proper model parameters for NdAl2, found in the literature. The existence of a minimum in magnetic entropy change below the phase transition was predicted and ascribed to the strong jump on the spin reorientation.