Comparative compressibility of Cu, Ag and Au

Abstract

X-Ray diffraction studies of the mixtures of Cu + Ag and Cu + Au were carried out at room temperature and under hydrostatic pressures over 100 kbar in a diamond-anvil pressure cell using both conventional and synchrotron X-ray sources. The difference in the d-spacings (Δ d) for the reflections having the same Miller index between these metals appears to be a linear function with pressure. Mathematical analysis yielded isothermal bulk moduli ( B 0) to be 1.167±0.007 Mb for Ag and 1.664±0.026 Mb for Au, assuming B 0 = 1.374 Mb for Cu. The results for both Cu and Au used and obtained in this study are in good agreement with those calculated from elastic constant measurements, but the bulk modulus for Ag agrees better with that derived from compressional studies than from elastic measurements.