【摘要】 用基质晶片作参比,测量了Cu⁺、Er³⁺等离子激活的钨酸锌晶体的光谱,并进行了分析讨论,发现激活离子与基质晶格之间存在能量传递过程.晶体在可见光区有比较强的荧光.更多还原

【Abstract】 The absorption, fluorescence and excitation spectra of zinc tungsta-te crystals activated by Ce3+, Cu+, Co2+, Ni2+ and Er3+ ions have been measured and studied with SHIMADZU UV-265 visible recording spect-rophotometer and RF-540 spectrofluorephotometer. Results show that most of the activated ions have strong absorption in UV range. When the absorption spectra were measured a thin zinc tungstate was used as the referential crystal instead of air to eliminate the influence of the host lattice because the existence of strong absorption in U.V range.The results obtained from the excitation spectrum measurements are similar to those from the absorption meausrements.The Cu+ ion has strong radiation in visible band (30C-600nm) when excited at 380nm with peak position at 460nm. We are intended to get 300-600nm tunable laser of Cu+ ion in ZnWO4:Cu crystal.We have obtained very strong green light (0.55UUUUUUUUUUm) from ZnWO4:Er crystal when excited at 380nm and 520nm corresponding to the transition of 2H9/2????????????4I13/2 and 4S3/2??????????4I15/2 respectively. This is partly due to the energy transfer process between the activated ion and the host lattice. We found that the absorption band of Er3+ ion overlapped with the emission band of the host lattice from the spectra, And the excitation spectrum of Er3+ in ZnWO4:Er crystal for Er3+ o.55UUUUUUUUUm emission at room temperature shows that there is an excitation band with peak position at 320nm in addition to the excitation lines due to the absorption of Er3 + itself. This new excitation band comes from the absorption of the host lattice. Obviously, the energy absorbed by the host lattice is partly transfered to Er3 + ion and so sensitized it according to energy transfer theory. Some experiments show that the ZnWO4:Er crystal can be used as laser material with wavelength at 0.55UUUUUUUUUm. The detailed results will be published in our other paper.Zinc tungstate crystal has strong absorption in UV range with peak wavelength at 317.6nm in which activators have strong absorption too, But the activators can get energy transfered from the host lattice to compensate the energy absorbed by the host lattice when the energy transfer process exists, which will decrease the excitation threshold on the other hand. This will improve the efficiency of crystal lasers.From our experiment results we believe that luminescent crystals like zinc tungstate can serve as good, host lattice of laser crystals in special cases更多还原