High-pressure structural and transport studies of orthorhombic Sm₂Ru₃Ge₅ compound

We report the results from high-pressure (HP) studies on orthorhombic U₂Co₃Si₅-structure type Sm₂Ru₃Ge₅ compound. HP synchrotron X-ray powder diffraction revealed a smooth reduction in the unit-cell volume up to ∼ 9 GPa which can be well described by a second-order Birch-Murnaghan equation providing the bulk modulus of the system to be ∼ 147 GPa. This system is found to have several Raman modes below 360 cm⁻¹ all of which show a hardening with pressure up to ∼ 9 GPa. Thus, there is no symmetry changing structural phase transitions in this system up to ∼ 9 GPa. The electrical resistivity under HP up to 3 GPa revealed that with increasing pressure, the anomaly related to the charge density wave transition shifted continuously to lower temperatures. In contrast, with increasing pressure, the anomaly associated with the antiferromagnetic transition at ∼ 7 K shows no detectable change.