Measuring Grüneisen Parameter of Lead by High Pressure-Jump Method

Using the technology of pressure jump, variations of temperature associated with pressure from 2.4GPa to 4.6GPa are measured for lead. The Grüneisen parameter is calculated from the thermodynamic relation γ= (K_s/T) (∂T/ ∂P)_s, in which substitution of △T/△P for ∂T/∂P at median pressure is strictly justified. The correction of temperature change is carried out by analysing the
experimental data, which makes the process more approaching to an
adiabatic condition. The calculated values of △T/△P and γ gradually decrease with the increasing pressure. The decrease trend is consistent with the previous work. The γ values in the range of 2--3GPa are averagely higher than the results of Ramakrishnan et al., indicating the effect of temperature correction. The improved method is promising for measurements of Grüneisen parameter to higher pressure range.