Cd_3Al_2Ge_3O_12锗酸盐石榴石中Cr^（3＋）的宽发射带和R线

BROAD EMISSION BAND AND R LINES OF Cr￣(3+) IONS IN Cd_3Al_2Ge_3O_(12) GERMANATE GARNETS

本文首次报道了掺杂不同浓度Ｃｒ３＋的Ｃｄ３Ａｌ２Ｇｅ３Ｏ１２锗酸盐石榴石在２９５Ｋ和７７Ｋ温度下的荧光光谱、Ｃｒ３＋的鲜红色宽带发射强度与激励功率的关系及荧光衰减．发现在Ｃｒ３＋的荧光光谱中存在从１５４００ｃｍ－１延伸到１１４００ｃｍ－１附近的宽带、两组Ｒ线及Ｒ线的Ｓｔｏｋｅｓ和反Ｓｔｏｋｅｓ振动光谱．２９５Ｋ时以宽带发射为主，７７Ｋ时宽带明显减弱，Ｒ线发射显著增强．在Ｃｄ３Ａｌ２Ｇｅ３Ｏ１２石榴石中，Ｃｒ３＋离子的光谱是由两个性质上稍有差异的Ｃｒ３＋中心发射组成的．

The spectroscopic preporties and fluorescence decay from Cr3+ ions in Cd3Al2Ge3O12 germanate garnets at 295 K and 77 K have been investigated for the first time. In Cd3Al2Ge3O12 garnet Cr3+ ions replaced A13+ ions occupy at octahedral sites with an intermediate crystal field. It was found that the fluorescence spectra of Cr3+ in this garnet consist of the broad emission band from 15400 cm-1 extending to about 11400 cm-1, two series of R lines and the weaker vibronic spectrum. At room temperature Cr3+ ions give the strong broad band emission, weaker R lines and vibronic spectrum of R lines, but at 77 K R lines dominate and the broad band decreases considerably. Analysing Cr3+ spectral results of the germanate garnet indicates that there are two Cr3+ emission centres to lead the complex emission spectra. The room temperature lifetimes of Cr3+ broad band emission are from about 570 μs to 300 μs as a function of Cr3+ concentration.