Refinement of the ruby luminescence pressure scale

A comparison of recent high pressure x-ray diffraction data for diamond and Ta with low pressure ultrasonic data provides a basis for the refinement of the ruby luminescence pressure scale; whereby not only the slope and curvature parameters A = 1904 GPa and B = 7.665 of the previous scale are changed, but evidence is given for a modified form for the ruby R-1 luminescence line shift under pressure with A = 1820 GPa, B = 14, and an additional parameter C = 7.3. This revised ruby pressure scale resolves to a large extent previous discrepancies between equation of state data derived from x-ray measurements on the basis of the currently used ruby scale; on the one hand, and ultrasonic or theoretical studies, on the other hand. (C) 2003 American Institute of Physics. [DOI: 10.1063/1.1525856].