Magnetic anisotropy and spin reorientation in Nd2Fe14B

We present calculations of the magnetic properties of Nd2Fe14B system using the laws of statistical thermodynamics in the mean field approximation. The energy of the system depends strongly on temperature via the temperature dependence of the five anisotropy constants of the tetragonal crystal. The classical partition function is evaluated and used to calculate the dependence of the magnetic properties on field and temperature. The calculated magnetization and magnetic heat capacity in the temperature range from 77 K to room temperature support the in-plane anisotropy and spin reorientation phenomena in Nd2Fe14B. Calculations of the torque and energy dependence on magnetic field and/or temperature are also reported. The findings of our method are in good agreement with both the experimental and theoretical work on this important material