Preparation And Properties Of Cerium-doped Yttrium Oxyorthosilicate And Lutetium Oxyorthosilicate For Scintillator

The Ce³+ doped yttrium oxyorthosilicate?Y₂SiO₅:Ce³+,YSO:Ce?and lutetium oxyorthosilicate?Lu2SiO5:Ce³+,LSO:Ce?has attracted a considerable attention.They have a lot of excellent performance,such as high output,high density,high atomic number,fast decay,radiation resistance,and good chemical stability compared to other scintillators,among which LSO:Ce is more better.For cutting down the cost,it has been proposed to substitute part of the Lu with Y in the formula,and the process of powder preparation can be optimized.In this thesis,Y₂Si0₅:Ce³+ and Lu₂Si0₅:Ce³+ powders were prepared by liquid phase precipitation method.And the effects of different condition on the powders phase structure and properties was investigated by X-ray diffraction?XRD?,SEM,TEM and spectral measurement.?1?The factor is temperature in this method,with which changed to investigate the powders structure,morphology and fluorescence properties.It was 1300? and 1200? that the transition temperature of the two powders from P2 1/c to C2/c respectively.The powders agglomeration was serious under high temperature and with the increase of temperature,the phenomenon was more serious.The fluorescence intensity of the powders were enhanced with the increase of temperature.?2?The influence of Y/Si ratio was studied on the phase structure at 1300°?.The boundary of the critical point was two.With the increase of the ratio of silicon,phase structure can transform Y₂SiO₅ into Y4.67?SiO4?3O.When the ratio reached one,the phase structure became Y2Si2O7.Y2O3 emerged if the ratio decline.?3?The impact of Ce-doping quantity was studied on fluorescent properties calcined at 1300?.The intensity of light of YSO:Ce enhanced with the increase of Ce until the concentration reaching 1.00%in N2.However concentration quenching wasn't found even the Cerium amount reaching 2.50%in H2.For LSO:Ce,The intensity of light began to decline at 0.25%in N2,and cerium concentration reached 2.00%was still no quenching in H2.In addition,the influence of dropping way and different atmosphere on the fluorescence properties of the powders were also investigated.The phase structure and morphology of the powders were compared with solid-phase method for demonstrating the advantages of the liquid phase precipitation method.