Study On Synthesis Of Lu₂SiO₅:Ce Ultra-fine Powder By Sol-Gel Method And Its Scintillation Property

In recent years, with the development of radiation medical devices, such as the X-ray computed tomography apparatus (X-CT) and positron emission tomography imaging device (PET), high-energy physics experiments widespread use, higher performance scintillator is required.Lu2SiO5:Ce(LSO:Ce) has been recognized as one of the best scintillating materials, which has high light output, short decay time, high-density, high atomic number, anti-radiation, small refractive index, stable physical and chemical properties and so on. LSO: Ce scintillator is mainly used in high energy physics and nuclear medicine. Therefore, LSO: Ce Scintillation Crystals have attracted a great deal of attention.In this thesis, preparation of LSO:Ce powder by sol-gel route was mainly studied, with XRD phase analysis, characterization of powder purity, SEM photographs, characterization of their morphology, UV excitation and emission spectra, characterization of their scintillation.In the acid-catalyzed sol-gel prepared LSO:Ce powder, the critical factor is pH value in sol-gel method, with which changed to investigate the LSO:Ce powder purity, morphology and scintillation properties. The experiments show that when the pH of reaction system is1.5prepared LSO:Ce powder is more purity, fine morphology and luminescence, and with the pH value of reaction system increased, LSO:Ce powder is less purity.The citric acid complexation sol-gel prepared LSO:Ce powder, in which we mainly investigate on the addition of citric acid and calcination temperature to purity, morphology and scintillation of LSO:Ce powder. The experiments show, when the mole ratio of citric acid and metal ions is2.5times, we prepared LSO:Ce powder from calcined dry gel,4hours at1100℃, which make us get high purity LSO:Ce powder. The average grain diameter of this kind of LSO:Ce powder’s primary particle is100nm; the average size of agglomerate particles is1micron. From this way, we prepared the LSO:Ce ultra-fine powder. Then, the calcination temperature has nothing to do with the scintillation of LSO:Ce powder.Meanwhile, this paper also researched on the LSO:Ce powder which prepared by co-precipitation, solid-phase method, and do a preliminary exploration on LSO:Ce ceramic sinter. The precursor of powder which prepared by co-precipitation takes the shape of spherical or nearly spherical and after calcination is good dispersion. By the initial sintering of the samples, we discovered that the powder’s dispersion is a critical effect to form intergranular pore of the LSO:Ce ceramic.