Measurement of mode Gruneisen parameters in PdD0.71and a calculation of d In Tc/dP

Abstract
Mode Gruneisen parameters ( gamma i) of transverse optic phonons, and a few selected acoustic phonons, have been measured by inelastic neutron scattering in PdD0.71. The results show gamma i for the optic modes between 3 and 6, which are somewhat higher values than those reported previously in the literature. Using the present results the authors have calculated d ln Tc/dP by the McMillan (1968) and Kakitani (1969) formulae and a reasonable agreement with experimentally measured values has been reached. They therefore conclude that d ln Tc/dP is dominated by the Gruneisen parameter of the optic modes.