Effect of titanium addition on the magnetic property of Nd 2Fe14B/α-Fe nanocomposite alloys

Rapidly solidified nanocrystalline a-Fe/Nd2Fe14B alloys with enhanced coercivity were obtained by melt spinning. The effects of Ti addition on the microstructure and magnetic properties of the nanocomposite a-Fe/Nd2Fe14B alloys were investigated by X-ray diffraction (XRD) and superconducting quantum interference device (SQUID) magnetometer. The analysis of XRD showed that Va-Fe estimated to be about 35.3 in the Ti-free a-Fe/Nd2Fe14B nanocomposites decreased down to 26.5 as the addition of was 5 at. Ti. Accordingly, adding Ti resulted in relevant improvements of magnetic properties, especially of the coercivity Hc from 595 kA/m up to 1006 kA/m. The dependence of M irrev(H)/2Mr on the reverse field H indicated that nucleation was the dominating mechanism for the magnetization reversal in these nanocomposites. The analysis of the temperature dependence of the demagnetization curve in the a-Fe/Nd2Fe14B nanocomposite magnets indicated that a reduction of aex could play a leading role in an increase in the coercivity of Ti-doped sample. © 2010 The Chinese Society of Rare Earths.