Crystal structures and elastic properties of Ti(Cu,Pt)2 and Ti(Cu,Pt)3 phases

This paper focused on the crystal structures of two new ternary phases, Ti(Cu,Pt)(2) and Ti(Cu,Pt)(3), which were studied by X-ray powder diffraction data using Rietveld method. Electron probe microanalysis was used for sample composition examination. Elastic properties of these phases were further measured by nano-indentation, and meanwhile calculated with first-principle (FP) calculations. It is found that the crystal structure of Ti(Cu,Pt)(2) is of orthorhombic cell space group Amm2 (No. 38) with structural prototype of VAu2. The resolved structure of Ti(Cu,Pt)(3) is of tetragonal AlPt3 type, belonging to the space group P4/mmm (No. 123). The nano-indentation measurement and FP calculations show that the elastic modulus of Ti(Cu,Pt)(2) increases firstly then decreases with Pt content, whereas that of Ti(Cu,Pt)(3) almost linearly increases with Pt content.