Temperature dependence of the ruby luminescence method for measuring high pressures

1089-7550

AIP Digital Archive

Physics

Pressures in diamond-anvil high-pressure cells often are determined by measuring ruby emission spectra because the R1 luminescence has high quantum efficiency and frequency of the R1 band shifts almost linearly with pressure, independent of temperature. To more than 600 K, pressures can be precisely determined by measuring luminescence spectra at ambient and high pressures at the same temperature. The temperature dependence of the frequency of the R1 line is not simple, and empirical approximations have been developed so that a pressure at a known temperature might be estimated from measurements of spectra at that P and T and at ambient pressure and one temperature; that is, without measuring the R1 line at ambient pressure at each temperature. Measurements reported here show that, between 100 and 260 K, pressures computed by using empirical approximations calibrated near ambient temperature may be in error from 0.1 to several GPa. The temperature dependence of the R1 line is accurately described by the function suggested by McCumber and Sturge [J. Appl. Phys. 34, 1682 (1963)]. Measurements at several temperatures between 100 and at least 400 K are needed to evaluate the precise parameters of this function appropriate for a particular spectrometer and ruby. Therefore, it is often practical for studies at pressures to a few GPa simply to determine the wavelength of the R1 line at a given temperature and ambient pressure by measuring it.

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