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The phase diagram of InSb has been studied by energy-dispersive X-ray diffraction with synchrotron radiation at pressures up to 8 GPa and temperatures up to 800 K in a Paris-Edinburgh cell. At room temperature InSb transforms above 2.5 GPa from the zincblende structure to a sixfoldcoordinated orthorhombic structure with Pmm2 (Cmcm) space group (InSb IV). In previous studies it was proposed that another orthorhombic structure with Immm space group (InSb 11) existed at higher temperature. We show that this phase is actually metastable, the InSb IV one being the stable form. The low-pressure melting curve and the triple point position are confirmed and the high pressure melting curve as well as the phase boundaries between the high pressure phases have been determined precisely. A new pressure-temperature phase diagram for InSb is established which eliminates contradictions in the previously proposed diagrams of its solid phases.

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Systematic tests of failure have been performed up to 700 MPa on 75 cylindrical sapphire windows of various thicknesses in the Poulter unsupported area geometry. Three distinct failure patterns are found to occur. The influence on the bursting pressure of the c-axis orientation, annealing, and fatigue are reported and discussed. Maximum working pressures are determined, as a function of the ratios of thickness and unsupported area diameter, to the window’s diameter.

X-ray absorption measumrrrelrts at tile b edge of Hg ill solid and liquid Mg' l' e have been perfortned under high-temperature and high-pressure up to 1000 K and 3 GPa using a large volume ParirtEdinburgB press. EXAFS spectra have been analyzed with GNXAS approach. The pressure dependencies of the nearest neighbor distance and the bond variance at room temperature as well as their variation with temperature at 0.6 GPa have been obtained. The temperature dependence of the bond variance Itas been fitted t o the Einstein tnodel and is wnsistellt to the decrease of the bulk modulus with increasing temperature, which has recently been shown to occur by an x-ray diffraction study.