Pressure dependence of the Raman spectra of salts of hexahydridoruthenate(II), M2RuH6 (M = Ca, Sr, Eu) and their deuteride analogues

Raman spectra of the calcium, strontium and europium salts of hexahydridoruthenate(II) and their deuterium analogues were measured as a function of pressure up to around 5 GPa. In all cases, the results gave graphs of increasing wavenumber with increasing pressure, which were linear in form. No pressure-induced phase transitions were observed over this pressure range. The dependences of the Raman wavenumbers on pressure and on the unit cell length were used to determine the bulk modulus, B 0, and the mode Grueneisen parameters, γ i, for each compound. These bulk moduli ranged from 12.9 to 18.8 GPa