Abstract
Raman spectroscopic studies were made for MgSiO3 perovskite, MgSiO3 garnet, and majorite with compositions of En60Py40 and En80Py20 synthesized at high pressure and high temperature. The frequencies of eight Raman active modes of MgSiO3 perovskite were measured at one atmosphere. Three modes with the frequencies, 388, 600 and 937cm−1, were observed for the first time. The frequency of Raman bands of the majorite solid solutions has very weak compositional dependence.
The pressure dependence of the two Raman peaks (602 and 932 cm−1 at one atmosphere) of MgSiO3 garnet was measured up to 26.3GPa using diamond anvill cell; these peaks correspond to the SiO4 internal vibration modes. The Raman frequencies increase lineary with increasing pressure. The mode Grüneisen parameters of these modes are deduced as 0.80 and 0.79.
