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, B0, and the mode Grüneisen parameters, γi, for each compound. These bulk moduli ranged from 12.9 to 18.8 GPa.