Potential use of the ruby <i>R</i>2 line shift for static high-pressure calibration

Abstract

Results of shock-wave experiments to examine ruby R-line shifts for uniaxial strain compression along the crystal a axis are summarized and compared with previous c-axis results [P. D. Horn and Y. M. Gupta, Phys. Rev. 39, 973 (1989)]. The present results show that R1-line shift with compression depends on both nonhydrostatic stresses and crystal orientation. Hence, pressure determination using R1-line shifts in a nonhydrostatic environment can lead to errors. In contrast, the R2-line shift depends only on density compression and is independent of nonhydrostatic stresses and crystal orientation. These findings suggest the use of R2-line shifts for pressure calibration under nonhydrostatic loading conditions.