Nanosized cerium-doped lutetium aluminum garnet （LuAG：Ce） phosphors were prepared by nitrate-citrate solgel combustion process using 1：1 ratio of the citrate：nitrate. The prepared LuAG：Ce phosphors were characte...Nanosized cerium-doped lutetium aluminum garnet （LuAG：Ce） phosphors were prepared by nitrate-citrate solgel combustion process using 1：1 ratio of the citrate：nitrate. The prepared LuAG：Ce phosphors were characterized by XRD, TEM, photoluminescence and radioluminescence spectra excited by UV and X-ray, respectively. The purified crystalline phase of LuAG：Ce was obtained at 900 ℃ by directly crystallizing from amorphous materials. The resultant Lu- AG：Ce phosphors were uniform and had good dispersivity with an average particle size of about 30 urn. Both photoluminescence and radioluminescence were well-known Ce^3＋ emissions located in the range of 470 -600 nm consisting of two emission bands because of the transition from the lowest 5d excited state （2D） to the 4f ground state of Ce^3＋, which matched well with the sensitivity curve of the Si-photodiode. There was a little red shift for the emission components from the UV-excited emission spectrum to the X-ray-excited emission spectrum. The fast scintillation decay component of 26 ns satisfies the requirements of fast scintillators.展开更多
以硝酸钇、硝酸铝为原料,采用溶胶—凝胶/燃烧合成结合法合成了钇铝石榴石(Y_3Al_5O_(12),YAG)超细微粉。用X射线衍射仪(D/Max-2550V型)及傅立叶红外光谱(FT-IR)确定前驱体和不同温度处理的粉末的相组成;借助于德国NETZSCH STA 449C TG...以硝酸钇、硝酸铝为原料,采用溶胶—凝胶/燃烧合成结合法合成了钇铝石榴石(Y_3Al_5O_(12),YAG)超细微粉。用X射线衍射仪(D/Max-2550V型)及傅立叶红外光谱(FT-IR)确定前驱体和不同温度处理的粉末的相组成;借助于德国NETZSCH STA 449C TG-MS热分析仪(升温速率为10℃/min)对前驱体粉末的热分解过程进行了研究,由JEM-200CX型透射电镜观察粉体的形貌。结果表明过多的柠檬酸和羧酸盐在400℃分解形成碳酸盐,在800℃YAG相开始逐渐形成,在900℃形成了结晶完全的YAG相,而没有中间相产生。经1000℃热处理获得了超细、分散良好、粒度为80 nm左右的均匀粉体。展开更多
Samarium-doped yttrium aluminum garnet (YAG∶Sm3+) phosphors were synthesized by nitrate-citrate sol-gel combustion method. Phase evolution, morphology and absorbency of the obtained materials were characterized by XR...Samarium-doped yttrium aluminum garnet (YAG∶Sm3+) phosphors were synthesized by nitrate-citrate sol-gel combustion method. Phase evolution, morphology and absorbency of the obtained materials were characterized by XRD, FESEM, reflection spectrum, respectively. The experimental results showed that single-phase cubic YAG∶Sm3+ crystalline was directly obtained at 800 ℃ from amorphous precursor, and mostly developed at 900 ℃. The prepared powders were relatively agglomerated with an average particle size of 300 nm. The reflection spectrum showed that there were several apparent characteristic absorption peaks due to the 4f→4f inner shell electron transitions from the 6H5/2 ground state to 6FJ (J=9/2, 7/2 and 5/2) excited state of Sm3+. Moreover, the intensity of the characteristic peaks was enhanced with the increasing concentration of Sm3+ ions.展开更多
基金Project supported by the National Defence Fundamental Research Project of China
文摘Nanosized cerium-doped lutetium aluminum garnet （LuAG：Ce） phosphors were prepared by nitrate-citrate solgel combustion process using 1：1 ratio of the citrate：nitrate. The prepared LuAG：Ce phosphors were characterized by XRD, TEM, photoluminescence and radioluminescence spectra excited by UV and X-ray, respectively. The purified crystalline phase of LuAG：Ce was obtained at 900 ℃ by directly crystallizing from amorphous materials. The resultant Lu- AG：Ce phosphors were uniform and had good dispersivity with an average particle size of about 30 urn. Both photoluminescence and radioluminescence were well-known Ce^3＋ emissions located in the range of 470 -600 nm consisting of two emission bands because of the transition from the lowest 5d excited state （2D） to the 4f ground state of Ce^3＋, which matched well with the sensitivity curve of the Si-photodiode. There was a little red shift for the emission components from the UV-excited emission spectrum to the X-ray-excited emission spectrum. The fast scintillation decay component of 26 ns satisfies the requirements of fast scintillators.
文摘以硝酸钇、硝酸铝为原料,采用溶胶—凝胶/燃烧合成结合法合成了钇铝石榴石(Y_3Al_5O_(12),YAG)超细微粉。用X射线衍射仪(D/Max-2550V型)及傅立叶红外光谱(FT-IR)确定前驱体和不同温度处理的粉末的相组成;借助于德国NETZSCH STA 449C TG-MS热分析仪(升温速率为10℃/min)对前驱体粉末的热分解过程进行了研究,由JEM-200CX型透射电镜观察粉体的形貌。结果表明过多的柠檬酸和羧酸盐在400℃分解形成碳酸盐,在800℃YAG相开始逐渐形成,在900℃形成了结晶完全的YAG相,而没有中间相产生。经1000℃热处理获得了超细、分散良好、粒度为80 nm左右的均匀粉体。
基金Project supported by 973 Research Project of China and Jiangsu Provincal Natural Sciences Fund (BK2007724)
文摘Samarium-doped yttrium aluminum garnet (YAG∶Sm3+) phosphors were synthesized by nitrate-citrate sol-gel combustion method. Phase evolution, morphology and absorbency of the obtained materials were characterized by XRD, FESEM, reflection spectrum, respectively. The experimental results showed that single-phase cubic YAG∶Sm3+ crystalline was directly obtained at 800 ℃ from amorphous precursor, and mostly developed at 900 ℃. The prepared powders were relatively agglomerated with an average particle size of 300 nm. The reflection spectrum showed that there were several apparent characteristic absorption peaks due to the 4f→4f inner shell electron transitions from the 6H5/2 ground state to 6FJ (J=9/2, 7/2 and 5/2) excited state of Sm3+. Moreover, the intensity of the characteristic peaks was enhanced with the increasing concentration of Sm3+ ions.
