  High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD)
studies were carried out on SmGdO3 (SGO) up to 25.7GPa at room temperature.
ADXRD results indicated a reversible pressure-induced phase transition from
ambient monoclinic to hexagonal phase at about 8.9 GPa. The observed
pressure-volume data were fitted into the third order Birch-Murnaghan equation
of state yielding zero pressure bulk moduli B0 = 132(22) and 177(22) GPa for
monoclinic and hexagonal phases, respectively. Pressure dependent micro-Raman
spectroscopy further confirmed the phase transition. The mode Gruneisen
parameters and pressure coefficients for different Raman modes corresponding to
each individual phase of SGO were calculated.
