High pressure structural studies on cubic phase of YInO₃

Multiferroic compounds have received a lot of importance because of their possible applications in memory devices. The compound YlnO₃ is useful to understand the geometric ferroelectric behaviour observed in YMnO₃ type multiferroic compounds. Synchrotron based high pressure angle dispersive X-ray diffraction experiments have been carried out on cubic phase of YlnO₃ up to ∼ 25 GPa. Our studies show that ambient cubic phase (Space Group Ia3¯) remains stable up to about 12 GPa. On further compression, ambient cubic phase transforms to orthorhombic phase (Space Group Pnma). Across the structural phase transition, the coordination of In atoms remain six while the coordination of Y atoms change from six to eight. The ambient phase persists up to highest pressure in the experiment (i.e. ∼25 GPa) which shows that the structural phase transition is first order in nature. On complete release of pressure, high pressure orthorhombic phase is recoverable in meta-stable state. Using third order Birch Murnaghan equation of state, the value of bulk modulus for Cubic phase is determined to be 161(14) GPa. (author)