Temperature and pressure dependence of the mode Grüneisen parameters close to the melting point in hexagonal ice

We reexamine the Pippard relations in this study by relating the specific heat CP to the Raman frequency shifts 1ν∂ν∂TP and the thermal expansivity αp to the 1ν∂ν∂PT, when the mode Grüneisen parameter depends on the temperature and pressure close to the melting point in hexagonal ice. From linear relations between them, the values of the slope dPdT are deduced in this crystal.Our slope values calculated here do not change significantly compared to those obtained when the mode Grüneisen parameter is taken as a constant close to the melting point in hexagonal ice.