Structural Study of R-Phase in Ti-50.23 at.%Ni and Ti-47.75 at.%Ni-1.50 at.%Fe Alloys

Abstract

The crystal structure of the R-phase was determined by combined use of the electron diffraction and the powder X-ray diffraction method. The Rietveld method was applied for the analysis of the powder diffraction data. The structure of the R-phase belongs to the space group P3 and is similar to that of ξ ' 2 Au-Cd martensite. The deviations of the atomic coordinates from the mirrorplane of the P31m are smaller than that of ζ ' 2 Au-Cd. The convergent beam electron diffraction patterns were also observed and discussed with the results.