Phase relations of the (Pr 1−x Sm x ) 2 Fe 14 B system.

The phase relations in the (Pr1−xSmx)2Fe14B system in a whole concentration range have been studied by means of X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS). The XRD patterns of the (Pr1−xSmx)2Fe14B samples have been refined by Rietveld method. These results reveal that all the alloys (Pr1−xSmx)2Fe14B are similar to the end member of the investigated system Pr2Fe14B with tetragonal structure (space group P42/mnm). The continuous solid solutions were formed in this system. The normalized lattice parameters and unit cell volumes of (Pr1−xSmx)2Fe14B solid solutions decrease linearly withxranging from 0 to 1.0. The DTA measurements show that the peritectic temperature of (Pr1−xSmx)2Fe14B increases with increasing Sm content and no metastable phases are detected. Based on the DTA data, SEM–EDS and XRD results, the vertical section of Pr2Fe14B–Sm2Fe14B in the Pr–Sm–Fe–B system has been constructed. [ABSTRACT FROM AUTHOR]