采用提拉法生长了质量较高的掺Fe铝酸锂(LiAlO2:Fe)晶体,并用吸收光谱、光致激发与发射光谱以及X射线激发发射(XEL)光谱测试等方法对晶体的光谱性质及结构进行了研究。结果表明,晶体对可见光与近红外光具有较高的透过,而在深紫外波段存在与Fe离子相关的吸收。以266 nm光激发得到710 nm的Fe3+离子的特征发射峰,分析表明晶体中Fe3+离子代替Li+离子而处于8面体格位。比较不同晶体样品的XEL光谱发现,空气退火后的γ-LiAlO2晶体出现了318 nm处较强的缺陷发光,而同样条件退火后的LiAlO2:Fe晶体与未退火的γ-LiAlO2晶体均未观察到相应的发光。分析得出此发光应与晶体退火后形成的F+心有关,而Fe掺杂可抑制晶体中Li2O的挥发,提高晶体的热稳定性。

A novel LiAlO2:Fe single crystal with good quality was grown by Czochralski method.The spectroscopic characteristics and structure of the crystal were studied by absorption spectrum,photoexcitation and emission spectra,and X-ray excited luminescence (XEL) spectra.The results show that the crystal is transparent in the visible-infrared range,while has absorption band related to the Fe doping in deep ultraviolet range,and the crystal shows the 710 nm typical Fe3+ peak when it is exited by 266 nm light.For the similarity of excitation and emission spectra to LiAlO2:Fe phosphor,the Fe3+ ions occupied the octahedral sites of Li+ in γ-LiAlO2 crystal.The XEL spectra show a strong emission band peaked at 318 nm for γ-LiAlO2 cryatal.It was concluded that the emission band at 318 nm should be related to F+ centers resulted from the loss of Li2O,whereas the Fe doping could restrain the evaporation of Li2O and improve the thermal stability of γ-LiAlO2 crystal.