本文用激光选位时间分辨光谱技术,研究了NdxY(1-x)PO4晶体系统的浓度猝灭和Nd~(3+)离子一离子相互作用。结果表明,浓度猝灭比五磷酸钕系统强,猝灭速率与 x~2有线性关系。激光选位时间分辨光谱揭示,在Nd(0.03)Y(0.97)PO4中,Nd~(3+)处于多种不等价的晶场格位中。由选位光谱对时间和温度的关系发现,处于不等价格位中的Nd~(3+)离子通过共振能量为δ=117cm~(-1)的二声子参助过程进行能量转移。确定了转移速率ωs=2.7×10~4s~(-1),室温下激发能量扩散系数为 D(300K)=2.15×10~(-9)cm~2·s~(-1)和扩散长度为 l(300K)=14.4×10~(-7)cm。

The concentration quenching of fluorescence and Nd3+ ion-ion interaction in NdxY1-xPO4 crystals were investigated by laser-excited time-resolved site-selective spectroscopy techniques. Results showed that the concentration quenching in such crystal is stronger than that in NdxY1-xPO4, and the quenching rate has a linear dependence on x2. The time-resolved site-selective spectra suggested that the Nd3+ iona occupy a variety of nonequivalent crystal-field sites in Nd0.03Y0.97PO4. From the dependence of site-selective spectra on time and temperature, it is believed that energy transfers between Nd3+ ions in nonequivalent crystal-field sites occur via two-phonon-assisted processes with, a resonant energy of 117 cm-1, an energy transfer rate ωs=2.7×104 s-1, a room-temperature diffusion coefficient D300 K=2.15×10-9 cm2 s-1, and a room-temperatisre diffusion length L300 K= 14.4×10-7 cm.