Fe-Ti metastable-phase formation by ion-beam mixing.

Abstract

The glass-forming ability of the Fe-Ti system by ion-beam mixing of multilayers at 300 K is investigated at three compositions: ${\mathrm{Fe}}_{83}$${\mathrm{Ti}}_{17}$ (close to eutectic), and ${\mathrm{Fe}}_{2}$Ti and FeTi (compositions of the equilibrium compounds). The formation of bcc ${\mathrm{Fe}}_{83}$${\mathrm{Ti}}_{17}$ is shown whereas an amorphous state is obtained at ${\mathrm{Fe}}_{2}$Ti and FeTi compositions. A good qualitative interpretation of the experimental results is given in the framework of metastable enthalpy curves and correlations with the equilibrium phase diagram are discussed. Rutherford-backscattering spectrometry of \ensuremath{\alpha} particles has been used to characterize the mixing efficiency. X-ray diffraction at glancing incidence and conversion-electron M\"ossbauer spectroscopy have been performed to investigate the short-range order in the glassy state.