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测量了 1 5～ 3 0 0K温度范围内 57 5%Al1 5O 3 5%CaO 7 5%BaO玻璃中四价铬的发射光谱。这种材料中铬离子的能级处于Tanabe Sugano图上弱场范围中 ,最低的激发态是3 T2 ,发射谱是一个宽带。按照单频近似理论拟合低温下的光谱 ,得到3 T2 能级的零声子线位置Ezp=84 0 0cm-1,声子能量 ω =3 2 0cm-1,黄昆因子S =3 58。尽管单频近似能够较好地描述低温下的线形 ,发射光谱宽度随温度的变化却与单频近似理论的结果不符。讨论了这种差别的原因 ,认为可能的解释是与激发态耦合的声子能量大于与基态耦合的声子能量。
The emission spectra of tetravalent chromium in 57 5% Al 1 5O 3 5% CaO 7 5% BaO glass were measured over a temperature range of 15-300 K. The chromium ion energy level in this material is in the weak field range of the Tanabe Sugano diagram, with the lowest excited state being 3 T2 and the emission spectrum being a broad band. According to the theory of single-frequency approximation, the zero-ray line Ezp = 84 0 0cm-1, phonon energy ω = 3 2 0cm-1 and Huang Kun factor S = 3 58 at 3 T2 level were obtained at low temperature. Although the single-frequency approximation can better describe the linearity at low temperature, the variation of the emission spectrum width with temperature does not accord with the single-frequency approximation theory. The reason for this difference is discussed, and a possible explanation is that the phonon energy coupled with the excited state is larger than the phonon energy coupled with the ground state.