The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each a...The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each as a function of layer thickness for different values of exchange interaction. The exchange interaction in each layer within the interface and the crystal field in the unit cell are studied. The magnetic coercive fields and magnetization remnants are obtained for different values of exchange interaction, different values of temperature and crystal field with fixed values of physical parameters.展开更多
The experimental results show that the coercivity of Nd-Fe-B sintermagnet decreases with increasing of the grain alignment degree of the magnets (i.e. decreasing of the orientation distribution coefficient σ).The coe...The experimental results show that the coercivity of Nd-Fe-B sintermagnet decreases with increasing of the grain alignment degree of the magnets (i.e. decreasing of the orientation distribution coefficient σ).The coercivities of the magnets with different orientation degree are calculated based on the pinning,nucleation and starting field theory,respectively.The comparison of the calculated values with the experimental results shows that the theoretical results are deviating from the experiments seriously for both pinning mechanism and nucleation mechanism. In contrast with that,the calculated values based on the starting field theory are in good agreement with the experimental results.展开更多
文摘The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each as a function of layer thickness for different values of exchange interaction. The exchange interaction in each layer within the interface and the crystal field in the unit cell are studied. The magnetic coercive fields and magnetization remnants are obtained for different values of exchange interaction, different values of temperature and crystal field with fixed values of physical parameters.
文摘The experimental results show that the coercivity of Nd-Fe-B sintermagnet decreases with increasing of the grain alignment degree of the magnets (i.e. decreasing of the orientation distribution coefficient σ).The coercivities of the magnets with different orientation degree are calculated based on the pinning,nucleation and starting field theory,respectively.The comparison of the calculated values with the experimental results shows that the theoretical results are deviating from the experiments seriously for both pinning mechanism and nucleation mechanism. In contrast with that,the calculated values based on the starting field theory are in good agreement with the experimental results.
