Pressure-induced phase transition inBaCrO4

Tony Huang, Sean R. Shieh, Arslan Akhmetov, Xi Liu, Chih-Ming Lin, Jiann-Shing Lee
2010 Physical Review B  
BaCrO 4 was studied to 25 GPa in a diamond-anvil cell using both Raman spectroscopy and x-ray diffraction methods. Our results showed that BaCrO 4 exhibits a phase transition near 9 GPa from both Raman and x-ray diffraction measurements. The new high-pressure phase ͑BaCrO 4 -II͒ is suggested as a monoclinic ͑P2 1 / m͒ structure, different from other high-pressure forms of ABO 4 -type compounds. Moreover, the high-pressure phase of BaCrO 4 is found to be reversible; the low-pressure phase is
more » ... essure phase is recovered at ϳ8 GPa upon decompression. The pressure-volume data of BaCrO 4 fitted to a third-order Birch-Murnaghan equation of state yield a bulk modulus of 53͑1͒ GPa and a pressure derivative of 6.8͑5͒, in agreement with the theoretical prediction. For the high-pressure phase BaCrO 4 -II, the bulk modulus is 117͑10͒ GPa and the pressure derivative is 3͑1͒.
doi:10.1103/physrevb.81.214117 fatcat:jdvyyubs7nd4jnzbv43xgek5z4