Study 4 Preparation And Characterization Of Nano CaWO

Calcium tungstate （CaWO₄） has a special luminescent properties and it is a perfectluminescent material, stimulate by X-ray UV and electron beam it can produce efficientblue, and the current the research and application of fluorescent has been mad greatprogress. CaWO₄nanomaterial are believed having a great deal of potential applications inmedical and health、quantum dot laser and single photon detection and so on. CaWO₄is ascintillation material can used in searching for dark matter. CaWO₄can deposited byvarious methods,such as high-temperature solid-phase method、sol-gel、micelles、microemulsion method have been reported, but little research with hard template method.By the method of sol-gel technology, CaWO₄powder was successfully fabricated. Andapplication of the sol-gel method and rotating smear wears combined prepared CaWO₄film one dimensional arrays were synthesized by sol-gel method and nanoporous aluminatemplate enhancement.In this paper, the work includes the following three aspects:1. By the method of sol-gel technology, good crystallinity CaWO₄was successfullyfabricated, using calcium acetate、ammonium tungstate、citric acid、ethylene as rawmaterial. The Photoluminescence （PL） result showed that with the increase of temperatureand the concentration increasing the intrinsic emission peak gradually enhanced andbroadened, the strongest emission peak at around420nm, and800℃is the optimumtemperature. It is shown by XRD and SEM that all the samples CaWO₄are pure and intetragonal system.2. CaWO₄thin films was prepared over glass surface by sol-gel process together withspin coating technique. and thin films were characterized by XRD，SEM and PL spectra.The results suggested that the strongest emission peak at407nm enhancement and blueshift with the temperature grew higher and the optimum temperature is700℃.Theanalysis of XRD and SEM indicated that the thin film crystallization is better in a lowerheating rate.Under the conditions of300℃the sample began crystallization and it fullycrystallized in the temperature700℃.3. CaWO₄one dimensional arrays were synthesized by sol-gel method andnanoporous alumina template enhancement and their were characterized by XRD，SEMand PL spectra. The photoluminescence data suggested that the luminescent spectrastrongest peak of the one dimensional arrays of calcium tungstate was410nm broadbandspectrum. Due to the sample and the template spectrum coupling results， thephotoluminescence peak had obvious blue shift. With the increase of temperature theintrinsic emission peak gradually enhanced. XRD and SEM showed that the smallerdiameter accorded with diameter holes.