HIGH-PRESSURE RAMAN-STUDY OF SRMOO4 UP TO 37 GPA AND PRESSURE-INDUCED PHASE-TRANSITIONS

Pressure-induced phase changes in SrMoO4 were investigated by high-pressure Raman spectroscopy in a diamond anvil cell, The scheelite-type SrMoO4 transforms in to a monoclinic lattice near 13 GPa and retains this structure up to 37 GPa, the limit of pressure tested. There is no pressure-induced amorphization in this simple molybdate up to this pressure, as in the case of structurally complex molybdate systems. The optical absorption characteristics of SrMoO4 change considerably with pressure, the sample turning progressively deep orange-brown with increase in pressure, This change is connected with the lowering of the d-state of molybdenum in the MoO4 ion with increase in pressure.