Melting curve determination under high pressure using pulsed laser heating in a diamond anvil cell: Application to cerium

Abstract

A new device for melting curve determination of metals under high static pressure has been developed in order to broaden the current investigatedranges in the P-T space. Experimentally, the sample is squeezed under argon by the two diamond anvils of a large numerical aperture cell which takes place between a pulsed YAG laser and a set of infrared detectors. During the dynamic laser heating, the light flux variations coming from a selected part of the sample surface opposite to the source are recorded at three different wavelengths and analyzed to get the true temperature ofsolid-liquid transitions. Under pressure, melting is determined on radiance curves froma plateau or a change of slope associated with emissivity variations. New results are shown and discussed for cerium. Above 3.3 GPa, the melting curve rises smoothly up to 1370K at around 30 GPa. A Simon's relationship is proposed.