Elastic properties of perovskite YCrO3 up to 60 GPa

The high-pressure evolution of the YCrO3 perovskite structure (space group Pbnm) has been investigated using synchrotron powder diffraction, up to 60 GPa. The results show an anisotropy in the elastic moduli of the individual crystallographic axes: the b axis is appreciably less compressible than both a and c axes [K-a0=195 (5) GPa, K-b0=223 (7) GPa, and K-c0=200 (6) GPa, respectively]. This implies that YCrO3 becomes more distorted with increasing pressure, which is similar to what was previously found in YTiO3 but opposite to the behavior reported for YAlO3. Such contrasting trends are explained by the stronger confinement of Y ions in YAlO3 due to the smaller size of octahedral network in the orthoaluminate compared to the orthochromate.