以CdO和MoO3粉料为初始试剂,通过高温固相烧结合成CdMoO4多晶料,采用坩埚下降法生长出尺寸达Φ25mm×130mm的透明完整CdMoO4单晶;应用DSC、XRD对所获单晶进行了结晶相和热性能表征,测试了单晶的紫外可见透射光谱、紫外光激发发射光谱及其发光衰减时间。结果表明,CdMoO4单晶具有良好的一致熔融析晶特性,采用坩埚下降法较易于生长出大尺寸单晶;该单晶在吸收截止边375nm以上波长具有良好光学透过性,在300nm紫外光激发作用下,测得该单晶具有525nm左右峰值波长的荧光发射,其发光衰减时间为804~1054ns。该单晶经氧气氛高温处理呈现出明显的退火消色效应,即经1000℃以上温度的氧气氛退火处理,可使晶体的光学透过性得以明显改善,其荧光发射强度显著增强。
Using CdO and MoO3 as initial agents,CdMoO4 polycrystalline material was synthesized by solid-state reaction at elevated temperature. Large transparent CdMoO4 single crystal with size of Φ25 mm× 130 mm was grown by vertical Bridgman process. The crystal sample was characterized by differential scanning calorimeter and X-ray powder diffraction. The transmittance spectra and photoluminescence spectra together with their decay time were measured. The results shows that the large-size crystals could be grown easily by vertical Bridgman method based on the fact that the crystal has a desirable crystallization characteristics with congruent melting behavior. The crystal wafers show a high optical transmittance in the wavelength range above the absorption edge of 375 nm. Under 300 nm ultraviolet photonic stimulation,the crystal wafers exhibit a fluorescence emission with a central wavelength at 525 nm or so with a decay time of 804-1054 ns. An evident colouration alleviation effect had been found in the crystal samples as the materials were annealed in oxygen atmosphere. After the crystals were annealed in oxygen atmosphere at the temperature above 1000 ℃,the optical transmittance was improved and the fluorescence emission was enhanced significantly.