"Pressure induced valence and structural phase transition in Ba2PrRu0.8Ir0.2O6"
B.J. Kennedy, L.Q. Li, Y. Lee, T. Vogt
Journal of Physics-Condensed Matter
Vol.16, No.18, pp.3295-3301, 2004.05
The crystal structure of the ordered double perovskite Ba2PrRu0.8Ir0.2O6 was investigated as a function of pressure at room temperature. High-resolution synchrotron powder diffraction measurements have revealed the occurrence of a first order phase transition at a critical pressure of about 0.5 GPa. Structural refinements indicate that Ba2PrRu0.8Ir0.2O6 transforms from an ambient pressure monoclinic (P 21/n) to a high-pressure tetragonal (P4/mnc) structure. The transition is consistent with a valence change of the Pr ions.