Silicon-Rich Corner of the Yb–Pt–Si Ternary System at 850°C

Abstract

We have studied phase equilibria in the silicon-rich part of the Yb–Pt–Si system. To this end, 22 alloys were prepared by a standard arc-melting process in an argon atmosphere and annealed at a temperature of 850°C. Physicochemical characterization of the samples included electron microscopy, X-ray microanalysis, X-ray diffraction, and differential thermal analysis. We have confirmed the existence of four previously known intermetallic compounds: YbPtSi, YbPt₂Si₂, Yb₃Pt₄Si₆, and Yb₂Pt₃Si₅. In addition, three new phases have been identified: YbPtSi₂, Yb₃₃Pt₁₇Si₅₀, and Yb₁₁Pt₃₃Si₅₆. The structure type of the YbPtSi₂ compound has been determined. We present statistical crystallographic data for the ternary phases and describe phase equilibria in the region studied in the 850°C isothermal section of the Yb–Pt–Si phase diagram.