Investigation of the magnetic properties of Dy doped Nd-Fe-B permanent magnet by using Mössbauer spectroscopy

Abstract

The crystal and the magnetic properties of (Nd35.00−xDyx)Fe bal. Cu0.15Co1.50Al0.20Nb0.35B1.00 (wt.%; x = 3.50, 6.00, and 8.00) samples are investigated by using x-ray diffractometer (XRD), vibrating smple magnetometer (VSM), and Mössbauer spectrometer. The crystal structure is determined to be tetragonal with the P 42/mnm space group. The saturation magnetization (Ms) decreases while the coercivity (Hc) increases with increasing Dy ion concentration. Based on the zero-filed-cooled (ZFC) curves, all the samples show spin reorientation, and the spin-reorientation temperature TSR decreases with increasing Dy ion concentration. The Mössbauer spectra measured at 295 K show decreasing < H hf > with increasing Dy concentration, and the abrupt changes both in the magnetic hyperfine field (H hf ) and the electric quadrupole shift (EQ) at temperatures around TSR.

Spin reorientation process in Tm2–xHoxFe14B – analysis of conical arrangement based on Mössbauer spectra

“…Many compounds based on the general formula R 2 Fe 14 B (R -rare earth element) have been studied so far, including the most common Nd 2 Fe 14 B which composes the strongest permanent magnets [1][2][3][4][5]. Tm 2 Fe 14 B and Ho 2 Fe 14 B also belong to this group.…”