Effect of temperature on the luminescence of Sm 3+ ions in YAM crystals

Abstract The spectroscopic features of samarium Sm 3+ activated Y 4 Al 2 O 9 (YAM) crystals are presented and discussed. Temperature sensing properties of Sm 3+ :YAM phosphor was demonstrated over the 300 - 1200 K range. Temperature dependent luminescence spectra and decay curves for the 4 G 5/2 level of Sm 3+ in YAM were measured. Ratio of the fluorescence intensities arising from the two close lying 4 F 3/2 and 4 G 5/2 levels (with energy separation of ΔE∼1000 cm −1 ) followed a straight line pattern, which confirms the Boltzmann distribution of the population, and can be used to measure temperature. The lifetime for the 4 G 5/2 level in 1% Sm doped sample decreases from 1.65 to 0.08 ms with heating from room temperature to 1200 K. This behavior of decays is discussed in terms of radiative and multiphonon decays as well as cross-relaxation dependence on temperature. 1. Introduction Spectroscopic properties of trivalent samarium (Sm 3+ ) ions in variety of dielectric hosts have been studied extensively over the recent years. Strong Sm