Determination of the phase diagrams of the Nd2Fe14B-Pr2Fe14B isopleth

The phase relations in the pseudo-binary Nd2Fe14B-Pr2Fe14B system were investigated and constructed by means of X-ray powder diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). The results revealed that similar to the end-members of the Nd2Fe14B-Pr2Fe14B system form a continuous solid solutions, all intermediate (Nd1−xPrx)2Fe14B samples belong to tetragonal Nd2Fe14B-type structure (space group P42/mnm). The lattice parameter a almost remains the same, and the lattice parameter c and unit-cell volume V increase linearly with an increase of Pr concentration. Based on the results of DTA measurements and X-ray powder diffraction examinations, the tentative phase diagram of the Nd2Fe14B-Pr2Fe14B isopleth has been constructed.