In-Situ High Pressure Raman Spectrum and Electrical Property of PbMoO₄

In-situ high pressure Raman spectra and electrical conductivity measurements of scheelite-structure compound PbMoO₄ are presented. The Raman spectrum of PbMoO₄ is determined up to 26.5GPa on a powdered sample in a diamond anvil cell (DAC) under nonhydrostatic conditions. The PbMoO₄ gradually experiences the transformation from the crystal to amorphous between 9.2 and 12.5GPa. The crystal to amorphous transition may be due to the mechanical deformation and the crystallographic transformation. Furthermore, the electrical conductivity of PbMoO₄ is in situ measured accurately using a microcircuit fabricated on a DAC based on the van der Pauw method. The results show that the electrical conductivity of PbMoO₄ increases with increases of pressure and temperature. At 26.5GPa, the electrical conductivity value of PbMoO₄ at 295K is 1.93×10^-4S/cm, while it raises by one order of magnitude at 430K and reached 3.33×10^-3S/cm. However, at 430K, compared with the electrical conductivity value of PbMoO₄ at 26.5GPa, it
drops by about two order magnitude at 7.4GPa and achieves 2.81×10^-5S/cm. This indicates that the effect of pressure on the electrical conductivity of PbMoO₄ is more obvious than that of temperature.