低温高压下的Na_5Eu(WO_4)_4的发光和晶体场参数

HIGH PRESSURE LOW TEMPERATURE LUMINESCENCE AND CRYSTAL PARAMETERS OF Na_5Eu(WO_4)_4

用低温金刚石对顶砧高压显微光谱系统在20—300K低温和0—10GPa高压范围内研究了白钨矿型化学计量的基质发光晶体四钨酸铕钠Na_5Eu(WO_4)_4中Eu^(3+)的发光.确定了Eu^(3+)荧光谱线和能级在低温下的压力移动率.它随温度变化,表明温度和压力对Eu^(3+)谱线作用不是独立无关的.按晶体场理论简化方法推导了能级的晶体场参数表达式,并按实验数据拟合出在不同低温下晶体场参数随压力的移动率.

Luminescence of Eu3+ in stoichiometric host luminescent crystal Na5Eu(WO4)4 has been studied under low temperature 20-300 K and hydrostatic high pressure 0 - 10 GPa using a diamon anvil high pressure and low temperature microspectroscopic system. We report for the pressure shift rates of spectral lines, energy levels and crystal field parameters of Eu3+ under low temperature. These pressure shift rates vary directly with temperature, and the experiment shows that the effects of temperature or pressure on the spectral lines of Eu3+ are not independent like that of R1 and R2 spectral line in ruby. According to crystal field theory, we have suggested a simplified method to derive the relations between energy levels and crystal parameters. The pressure shift rates of crystal parameters at low temperature(△Bkg/△p)T have been determined by fitting with the experimental spectral data.