LiYF_4晶体的色心

Colour Centre in LiYF_4 Crystal

用^(60)Co—γ射线辐照 LiYF_4 晶体,可使晶体从紫外到可见产生多个色心吸收带。本文测得了峰值为275nm、335nm、430nm,530nm、555nm 和630nm 的六个σ吸收带,及峰值为255nm、335nm、410nm、530nm、555nm 和630nm 的六个π吸收带,在低温下还观察到波长为0.72μm,1.16μm、1.63μm 的三个宽带荧光,其激发峰分别位于415nm、470nm、630nm、555nm;并发现吸收位于630nm 的色心和吸收位于555nm 的色心在各自的吸收光照射下会相互转化。认为吸收位于630nm 和吸收位于555nm 的色心为两种不同构型的 F_2心。

Some absorption bands of colour centers were observed in therange from ultraviolet to visible regions when LiYF_4 crystals were irradiatedby^(60)C_(o-γ),ray.They are six σ absorption bands at 275nm,335nm,430nm,530nm,550nm and 630nm and other six π absorption bands at 255nm,335nm,410nm,530nm,555nm,and 630nm.It was also observed at LNT that thereexisted three broad fluorescence bands of wave lengths 0.72μm,1.16μm and1.63μm with exciting peaks at 415nm and 470nm,630nm and 555nm,repecti-vely.It was discovered that the colour centers with absorption bands at 630nm and 555nm could be transformed into one another when they wereilluminated by the light of corresponding absorption wavelengths.Experimentalresults indicate that the colour centers at 630nm and 555nm are the F_2 centersof different types.