The structural behaviour of Cu0.5Fe0.5Cr2S4 has been studied experimentally and theoretically at pressures up to 44GPa. The experiments are supported by density functional calculations using the full-potential linear muffin-tin orbital method for investigating ground state properties and high-pressure behaviour. We report here the first experimental and theoretical determinations of the bulk modulus: B0=106(2)GPa and B′'0=4.0 (experimental), and B0=96GPa and B′0=3.9 (calculated). Moreover, a pressure-induced structural and electronic phase transformation occurs at 14.5GPa accompanied by a volume collapse of about 6%. Tentatively, the high-pressure phase is assigned the defect NiAs structure of Cr3S4 type with space group I2/m (12). The mechanism of the phase transition is explained by a Jahn–Teller type distortion, associated with geometrical frustration and magnetic spin changes.
Journal of Alloys and Compounds, 2013, Vol 578, p. 202-207