化学法制备Nd-Fe-B颗粒退火产物的物相调控

Phase regulation of annealing products by chemically prepared Nd-Fe-B particles

为了制备具有优良性能的Nd-Fe-B颗粒,在等时变温退火和等温变时退火的基础上,深入研究了温度和时间对Nd-Fe-B氧化物物相组成和百分含量变化的影响,然后对物相进行调控。最终确定了合理的退火温度和退火时间,成功制备出了以Nd_2Fe_(14)B为主相的Nd-Fe-B纳米颗粒。通过XRD、Rietveld精修拟合、SEM、TEM、VSM检测分析,结果显示Nd-Fe-B氧化物主要由FeNdO_3,NdBO_3和α-Fe组成,最佳的退火温度为750℃,最佳的退火时间为5 h,最终获得的Nd-Fe-B氧化物分别为54.619%的FeNdO_3,19.901%的α-Fe,11.760%的NdBO_3。利用该氧化物成功制备出含有88.457%的Nd_2Fe_(14)B和11.543%的Fe_3B纳米粒子的Nd-Fe-B颗粒,该颗粒的矫顽力约206.96 kA/m。

Aiming to prepare Nd-Fe-B particles with excellent properties, based on the previous research on isochronous temperature annealing and isothermal annealing, the effects of temperature and time on the composition and percentage of Nd-Fe-B oxides were studied, respectively. Accordingly, the physical phase was adjusted. As a result, the optimal annealing temperature and time were determined. Nd-Fe-B nano particles with Nd2Fe14B as the main phase were prepared. Furthermore, the phase transition and magnetic properties were analyzed by X-ray diffractometer(XRD), Rietveld refinement fitting, scanning electron microscope(SEM), transmission electron microscope(TEM) and vibration sample magnetometer(VSM) detection. The results show that the Nd-Fe-B oxide mainly consisted of FeNdO3, NdBO3 and α-Fe. 750 ℃ and 5 h have been found to be the optimal annealing temperature and time, respectively. The Nd-Fe-B oxide obtained included 54.619%, FeNdO3, 19.901% α-Fe, and 11.760% NdBO3. Then this oxide was used to prepare Nd-Fe-B nanoparticles containing 88.457% of Nd2Fe14B and 11.543% of Fe3B nanoparticles with the coercivity of 206.96 kA/m.