Revised phase diagram for the Nd–Pt system from 35 to 85 at% platinum

The phase diagram of the Nd–Pt system from 35 to 85 at%Pt has been revised using X-ray diffraction and differential thermal analysis. It is found that the Nd₃Pt₄ phase with the rhombohedral Pd₄Pu₃ structure type is unstable and decomposes into the two neighboring phases NdPt and NdPt₂ at temperatures ranging approximately from 583 to 1123 K. It is confirmed that the homogeneity range for the Laves phase NdPt₂ extends from about 68.5 to 75.3 at%Pt in the Nd–Pt binary system. The polymorphic transformation temperature of α-NdPt ⇌ β-NdPt is about 623 K, where the α-NdPt phase with BFe type is stable at low temperatures and the β-NdPt phase with BCr type at high temperatures.