Abstract
The Ni-Pt phase diagram was corrected in the range of 15–85 at.% Pt and in the temperature range of 400–525 °C using powder X-ray diffraction data. To reduce the time required to achieve the equilibrium state, Ni-Pt alloys, consisting of 80–140 nm nanocrystalline particles (nanoalloys) were used as initial samples. The nanoalloys were synthesized by thermolysis of specially prepared multicomponent precursors. Phase transformations in the system at high temperatures were studied in situ by X-ray diffraction. The boundary positions of Ni1?xPtx (A1), Ni3Pt (L12), NiPt (L10), NiPt3 (L12) single-phase regions were corrected.