Pressure dependence of spectral positions and widths of emission lines related to 5DJ→7FJ electronic transitions in Sm2+ ions doped into SrFCl single crystal

The pressure dependence of the peak positions and widths of the fluorescence lines corresponding to the 5DJ→7FJ electronic transitions in Sm2+-doped SrFCl crystals was measured at room temperature (RT) with a diamond anvil cell (DAC) and a high-pressure gas system, using silicone oil and gaseous helium as the pressure-transmitting medium, respectively. At RT and ambient pressure the electronic transitions 5D0→7FJ (J= 0, 1, 2, 3) and 5D1→7FJ (J=0, 1, 2) in Sm2+ ions yielded rather sharp spectral lines peaked at 14490, 14206, 13685, 13012 cm−1 and 15823, 15533, 15012 cm−1, respectively. At pressures up to 45 kbar in the DAC all these peaks shifted linearly to lower energies at the rates −2.36, −2.10, −2.43, −2.22 cm−1/kbar and −2.35, −2.33, −2.47 cm−1/kbar. Under purely hydrostatic gas pressure up to 7 kbar at RT the initial (normal pressure) widths of the 5D0→7F0, 5D0→7F1 and 5D1→7F0 lines having a Lorentzian profile (with corrected FWHM values of 1.55, 5.71 and 1.97 cm−1) decreased linearly with increasing pressure at the rates −0.009(2), −0.077(3) and −0.034(2) cm−1/kbar, respectively. Possible mechanisms of the observed pressure effects are discussed. For further studies of linewidth variations with the pressure, gaseous helium as a best possible high-pressure medium is strongly recommended.