Mössbauer studies of the N50 permanent magnet

Abstract

The crystal and the magnetic properties of the N50 permanent magnet, which is widely used in industrial applications, have been studied by using x-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and Mössbauer spectrometer. The crystal structure was determined to be tetragonal with a Nd-Fe-B structure. Based on the M -T curves, the values of spin reorientation temperature (TSR) and Curie temperature (TC ) were found to be 130 and 600 K, respectively. The Mössbauer spectra of N50 showed abrupt changes in the magnetic hyperfine field (H hf ) and the electric quadrupole shift (EQ) at temperatures around 130 K, indicating a spin reorientation (TSR). From the Mössbauer absorption area as a function of the square of the temperature for the N50 permanent magnet, the Debye temperature (ΘD) was found to be ΘD = 414.7 K.