摘要
The magnetic effect and the magnetocaloric effect in La_2NiMnO_6（LNMO） double perovskite are studied using the Monte Carlo simulations.The magnetizations,specific heat values,and magnetic entropies are obtained for different exchange interactions and external magnetic fields.The adiabatic temperature is obtained.The transition temperature is deduced.The relative cooling power is established with a fixed value of exchange interaction.According to the master curve behaviors for the temperature dependence of △S_m^（max） predicted for different maximum fields,in this work it is confirmed that the paramagnetic-ferromagnetic phase transition observed for our sample is of a second order.The near room-temperature interaction and the superexchange interaction between Ni and Mn are shown to be due to the ferromagnetism of LNMO.
The magnetic effect and the magnetocaloric effect in La_2NiMnO_6（LNMO） double perovskite are studied using the Monte Carlo simulations.The magnetizations,specific heat values,and magnetic entropies are obtained for different exchange interactions and external magnetic fields.The adiabatic temperature is obtained.The transition temperature is deduced.The relative cooling power is established with a fixed value of exchange interaction.According to the master curve behaviors for the temperature dependence of △S_m^（max） predicted for different maximum fields,in this work it is confirmed that the paramagnetic-ferromagnetic phase transition observed for our sample is of a second order.The near room-temperature interaction and the superexchange interaction between Ni and Mn are shown to be due to the ferromagnetism of LNMO.
