Phase structure of the Ti₁Cu₁− _x Fe _x system

Abstract

The phase structures of Ti₁Cu_1−X Fe _X withX=0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 were investigated by means of Mössbauer spectroscopy, X-ray diffraction, and microprobe. The Mössbauer spectral and X-ray diffraction data imply that the γ-TiCu and CsCl structure phases coexisted in theX=0.1 andX=0.2 alloys. The Mössbauer spectrum ofX=0.1 is a sum of two components, one quadrupole doublet with larger quadrupole splitting and one with smaller quadrupole splitting. Mössbauer spectra for alloys other thanX=0.1 are simple doublet. By comparison, Ti₁Cu_0.5Fe_0.5 has smaller linewidth and higher isomer shift than Ti₁Co_0.5Fe_0.5. This might be attributed to stronger interaction between Cu and Fe than that between Co and Fe. The solid solubility of Fe in the γ-TiCu lattice is very limited to about 1 at. pct. On the contrary, CsCl structure phase is homogeneous in the range of Ti₁Cu_1−X Fe _X ,X=0.25 to maybeX=1. The lattice parameter of CsCl structurevs concentration of Cu is related linearly.