LiF晶体F3+色心的实验研究

本文从实验上系统地研究了在不同条件下电子束辐照LiF晶体所形成的F₃⁺色心的光学特点。并且由荧光光谱分析了F₃⁺心和F₂心,的相对密度关系。实验表明,辐照温度对于色心的形成和密度的相对大小起着关键的作用。主要实验结果包括:1)在液氮温度下辐照,然后在暗处加热至室温可形成高密度的F₃⁺心,表现在发射光谱中F₃⁺心荧光占绝对优势。吸收光谱表明没有N心和R心。2)由动力学荧光谱可以看到低温辐照的样品在F₂⁺心衰变的同时,F₃⁺心密度迅速增加。而室温辐照的样品则是F₂心,与F₃⁺心的密度以近似相等的速率增加。3)详细观察了F₃⁺心530nm荧光激发带与F₂心670nm荧光激发带半宽度的变化和双峰结构。由此对M吸收区的发光特点作了解释。 关键词：

EXPERIMENTAL STUDIES OF F3+ COLOR CENTERS IN LiF CRYSTAL

In this paper, we describe systematically some experimental results of the optical characters of the creaion of F₃⁺ centers in LiF crystal by electron bombardment under different conditions. The relative density between F₃⁺ and F₂ centers are analysed from fluorescence spectra. The experimental results show that irradiation temperature plays an important role in the creation of F₃⁺ and F₂ centers and affects the relative density of F₃⁺ and F₂ centers. The main results are as follows: (1) Irradiation at liquid nitrogen temperature and then warming up to room temperature in the dark can create F₃⁺ canters with high density, which can be seen from the fluoreseence spectra, as fluorescence of F₃⁺ centers centered at 530 nm is much stronger than that of F₂ center (670 nm) and fewer N centers and R centers are presented in absortion spectra. (2) From dynamic fluorescence spectra, it can be shown that in the samples irradiated at liquid nitrogen temperature, the density of F₃⁺ centers increase rapidly when F₂⁺ centers decays. But in the samples irradiated at room temperature the growth of F₃⁺ and F₂ centers are approximatly with the came rate. (3) We observd the band width and double pike structure of the fluorescence excitation spectra of F₃⁺ and F₂ centers.