High pressure structural studies on SrRuO3

We have performed room temperature high pressure structural studies on the ferromagnetic perovskite SrRuO3 to 34 GPa. We have also used three different pressure media (silicone fluid, 4:1 methanol:ethanol and argon) to test for possible effects of pressure media on compression data. The orthorhombic perovskite structure is stable to the highest pressure, and the data can be fit with a bulk modulus of B-0 = 192(3) GPa with a pressure derivative of B-0' = 5.0(3) for all of the pressure media. We have also examined the high pressure behavior of the RuO6 octahedra using a model that assumes the octahedra are not distorted. Various tilt angles around the ideal cubic perovskite axes are found and can be used to estimate the Ru-O-Ru bond angle that is known to be directly related to the ferromagnetic Curie temperature. For all pressure media, there appears to be a minimum in the Ru-O-Ru bond angle around 15 GPa. Implications for the observed high pressure magnetic behavior of SrRuO3 will be discussed. (C) 2008 Elsevier Ltd. All rights reserved.