Growth of the photoacoustic phase signal difference Δφ in MgO:Cr³⁺ as a possible new method for measuring high pressure in the diamond anvil cell

Abstract

The possible application in the growth of the photoacoustic phase signal Δφ in MgO:Cr3+ crystal, caused by pressure, as a new method for the measurement a high pressure in the diamond anvil cell, has been considered. The method is based on: 1) a modified three energy level model which has been successfully applied on ruby [1], and 2) on the experimental confirmed fact that changing the relevant physical quantities caused by high pressure in the MgO:Cr3+ crystal, are several times larger than in ruby and alexandrite (2). Δφ nonlinearly increase in the considered pressure range. It was obtained the functional dependence between Δφ and pressure which caused its growth. At 12GPa the value of Δφ is 60 times greater than at a pressure of 1 bar.