Progress in research of garnet scintillation ceramics

Recently, Li Jiang's team, a researcher of Shanghai Silicate Research Institute of Chinese Academy of Sciences, controlled the concentration and trap depth of shallow level defects in luag scintillating ceramics through "energy band engineering" and "defect engineering" The designed and prepared luyag: PR and luag: CE, Mg scintillating ceramics have a light output of 24400 pH / MeV and 25000 pH / MeV respectively It is reported that this is the highest light production of the same kind of scintillation ceramics in the world Relevant research results were published in physics review application (Phys Rev Applied, 2016, 6:064026) and advanced optical materials (adv opt Mater., 2016, 4:731) As a key component of scintillation detector, scintillation materials are widely used in high-energy physics, medical imaging, oil exploration and other fields However, the defects in scintillation materials will affect the performance of scintillation detectors because they capture the carriers in the transport process, delay the scintillation and reduce the light production The research team used the first principle calculation, low-temperature thermoluminescence and synchrotron radiation to characterize the existence form and defect concentration of defects in materials The mechanism of "band engineering" and "defect engineering" is put forward, and luyag: PR and luag: CE, Mg are designed and prepared The shallow level defects in the materials are successfully suppressed, and the comprehensive scintillation performance of the materials is improved The substitution of Y 3 + for luag: PR is different from the general ion substitution The radius and chemical properties of Y 3 + and Lu 3 + are similar After substitution, no additional energy levels will be added in the band gap, but the band gap width will be reduced, and the concentration of shallow level defects in the material, which are mainly reverse defects, will be reduced Low temperature thermoluminescence showed that the defect concentration in the designed material decreased significantly The results of optical output attenuation dynamics test show that the slow emission component is less than 30% and the light yield is increased by 20% (Phys Rev Applied, 2016, 6:064026) By controlling the ratio of Ce4 + / Ce3 +, Mg2 + - doped luag: CE can reduce the influence of electron trap defects on carrier transport, and the optical yield of the material is more than 50% of that of luag: CE single crystal Scintillation decay test shows that the fast light component in the material reaches 60% (adv opt Mater., 2016, 4:731) Shanghai Silicate Institute has made important progress in the research of garnet scintillation ceramics: function dozoom (size) {var tdtxt = document Getelementbyid ("zoom"); VAR element = tdtxt Getelementbytagname ("*"); if (element Length = = 0) {tdtxt Style Fontsize = size + 'PX';} else {for (VaR I = 0; I & nbsp; "); elsedocument Write (" 1 & nbsp; "); for (VaR i=1; i ");elsedocument.write(""+(i+1)+" ");}return "";}function createPageHTML(_nPageCount, _nCurrIndex, _sPageName, _sPageExt){if(_nPageCount == null || _nPageCount 2 Next >> ");}else if (nCurrIndex == 1){document.write(" 1 2 ");}}else{if(nCurrIndex == 0){document.write(num(_nPageCount, _nCurrIndex, _sPageName, _sPageExt));document.write("Next ");}else if (nCurrIndex == 1){document.write("Previous ");document.write(num(_nPageCount, _nCurrIndex, _sPageName, _sPageExt));document.write("Next ");}else if(nCurrIndex == (_nPageCount-1)){document.write("Previous ");document.write(num(_nPageCount, _nCurrIndex, _sPageName, _sPageExt));}else{document.write("Previous ");document.write(num(_nPageCount, _nCurrIndex, _sPageName, _sPageExt));document.write("Next ");}} }
Fig (a) theoretical calculation of luag band structure; (b) theoretical calculation of luyag band structure; (c) schematic diagram of Y 3 + substitution mechanism