Pressure dependence of Sm:YAG fluorescence to 50 GPa: A new calibration as a high pressure scale

The pressure-induced wavelength shift of laser excited fluorescence from samarium doped yttrium aluminum garnet (Sm:YAG) was measured up to 50 GPa at room temperature against the R1 shift of ruby. The intense peaks between 618 and 611 nm were analyzed as triplet, Y1, Y2, and Y3, by curve fitting analysis using the Lorentzian function. The Y1 (λ0=618 nm) peak was the strongest peak up to 40 GPa, while the Y2 (λ0=616 nm) peak became the strongest above it. Based upon the pressure dependency of the Y1 and Y2 peaks, the following pressure scales are proposed: P=3.25×Δλ(Y1)–0.015×Δλ2(Y1); P=4.03×Δλ(Y2)–0.055×Δλ2(Y2). As the temperature dependence of the fluorescence shift of Sm:YAG is negligibly small, these pressure scales will be useful for high pressure and high temperature experiments using a diamond anvil cell.