在353K的乙酰胺-尿素-N aB r熔体中,P t、Cu电极上,Co(Ⅱ)+2e→Co(0)是一步完全不可逆反应,测得0.060m o l.L-1CoC l2-乙酰胺-尿素-N aB r中,Co(Ⅱ)在P t上,传递系数α=0.28,扩散系数D0=4.68×10-5cm2.-s 1,Cu上α=0.28,D0=4.06...在353K的乙酰胺-尿素-N aB r熔体中,P t、Cu电极上,Co(Ⅱ)+2e→Co(0)是一步完全不可逆反应,测得0.060m o l.L-1CoC l2-乙酰胺-尿素-N aB r中,Co(Ⅱ)在P t上,传递系数α=0.28,扩散系数D0=4.68×10-5cm2.-s 1,Cu上α=0.28,D0=4.06×1-0 7cm2.-s 1。G d(Ⅲ)不能单独还原为G d(0),但可以被Co(Ⅱ)诱导共沉积。由恒电位电解法得到非晶态的G d-Co合金,G d的含量随阴极电位的负移,G d(Ⅲ)/N i(Ⅱ)摩尔比增大以及电解时间延长而增大。展开更多
With the pretreatment of pyrolysis, the uniform, smooth, dense and crack free Gd2O3∶Eu3+ films were obtained by sol-gel process without shielding atmosphere. Atomic force microscopy （AFM）, X-ray diffraction （XRD）...With the pretreatment of pyrolysis, the uniform, smooth, dense and crack free Gd2O3∶Eu3+ films were obtained by sol-gel process without shielding atmosphere. Atomic force microscopy （AFM）, X-ray diffraction （XRD）, Ellipsometry, transmission, photoluminescence and X-ray excited emission were applied to study to the surface morphology, structure, thickness and optical properties of the films. The results show that the films are made up of grains with cubic structure in average size about 22 nm. With 21 times reproducible spin coating and pyrolysis treatment, the thickness of the film could reach to 792 nm and the transmittance of the film in visible region is above 90%. Two peaks at 223 and 250 nm are found in excitation spectra, which correspond to host lattice （HL） excitation and charge transfer （CT） excitation, respectively. Meanwhile, the main peak relates to HL excitation which is contrary to that of Gd2O3∶Eu3+ powder. This phenomenon will be beneficial to radioluminescence. The emission spectra show that the main peak located at 611 nm could be excited either by UV or X-ray, which correspond to （（）7F2→（）5D0） transition in Eu3+ ions. The luminescence intensity at 10 ms is only 10-4 time of that at 10 μs, which means that the afterglow in Gd2O3∶Eu3+ films is insignificant for X-ray imaging.展开更多
文摘With the pretreatment of pyrolysis, the uniform, smooth, dense and crack free Gd2O3∶Eu3+ films were obtained by sol-gel process without shielding atmosphere. Atomic force microscopy （AFM）, X-ray diffraction （XRD）, Ellipsometry, transmission, photoluminescence and X-ray excited emission were applied to study to the surface morphology, structure, thickness and optical properties of the films. The results show that the films are made up of grains with cubic structure in average size about 22 nm. With 21 times reproducible spin coating and pyrolysis treatment, the thickness of the film could reach to 792 nm and the transmittance of the film in visible region is above 90%. Two peaks at 223 and 250 nm are found in excitation spectra, which correspond to host lattice （HL） excitation and charge transfer （CT） excitation, respectively. Meanwhile, the main peak relates to HL excitation which is contrary to that of Gd2O3∶Eu3+ powder. This phenomenon will be beneficial to radioluminescence. The emission spectra show that the main peak located at 611 nm could be excited either by UV or X-ray, which correspond to （（）7F2→（）5D0） transition in Eu3+ ions. The luminescence intensity at 10 ms is only 10-4 time of that at 10 μs, which means that the afterglow in Gd2O3∶Eu3+ films is insignificant for X-ray imaging.
