Structural phase transition of ternary high-k dielectric SmGdO3:   Evidence from ADXRD and Raman Spectroscopic Studies
  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. 
Yogesh Sharma, Pankaj Misra, Satyaprakash Sahoo, A. K. Mishra, S. M.   Sharma, and Ram S. Katiyar
cond-mat.mtrl-sci