Search

By using the effective field theory (EFT), the mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model adapted to a double perovskite structure has been studied. The EFT calculations have been carried out from Ising Hamiltonian by taking into account first and second nearest-neighbors interactions and the crystal and external magnetic fields. Both first- and second-order phase transitions have been found in phase diagrams of interest. Depending on crystal-field values, the thermodynamic behavior of total magnetization indicated the compensation phenomenon existence. The hysteresis behaviors are studied by investigating the reduced magnetic field dependence of total magnetization and a series of hysteresis loops are shown for different reduced temperatures around the critical one. [ABSTRACT FROM AUTHOR]

Within an effective field theory we investigate the anisotropy of an antiferromagnetic coupling and the Ne´el temperature in a diluted spin-7/2 Ising model. The bond dilution (p) effect in the Ne´el temperature is shown in (TN,p) plane for some selected values of anisotropic parameter αc=Jc/J. The temperature dependence of the magnetic moment has been studied for some values of p and αc. [Copyright &y& Elsevier]