Studies on magnetic and magnetocaloric properties of double perovskite La2NiMnO6 system.

The present work aims to make an estimate of the adiabatic temperature change ( Δ T add ) parameter due to the magnetocaloric effect (MCE), for the rare-earth (RE)-based double perovskite La 2 NiMnO 6 system. Isothermal magnetization ( M versus H ) measurements are carried out on the La 2 NiMnO 6 sample, at temperatures around the ferromagnetic phase transition temperature ( T C ). The experimental magnetization data of La 2 NiMnO 6 are analyzed by using the Weiss mean-field model theory (MFT) and Landau theory of phase transitions. The magnetocaloric properties such as the isothermal magnetic entropy change ( Δ S M ), refrigerant capacity (RC) and the adiabatic temperature change ( Δ T add ) are evaluated using the experimental and numerically computed/simulated data. For the estimation of the adiabatic temperature change, the heat capacity data of La 2 NiMnO 6 system are generated using the mean-field model data and the reported Debye temperature ( Θ D ) value of La 2 NiMnO 6 . Additionally, Monte Carlo simulations are performed for the La 2 NiMnO 6 system, using Ising model Hamiltonian. The magnetocaloric properties are also extracted from the Monte Carlo simulations data. The La 2 NiMnO 6 shows a maximum adiabatic temperature change of around 2.3 K for the magnetic field change from zero to 70 kOe. [ABSTRACT FROM AUTHOR]