论文部分内容阅读
The dynamic process of the ionic valence changing from Eu~(2+) to Eu~(3+) in EuF_2 at high temperature has been investigated by ESCA, high,temperature X-ray diffraction, high temperature spectrum, high temperature magnetic Isusceptibility and Mssbauer spectrum. It has been shown that the formed Eu~(3+) exists in different compounds when EuF_2 is heated to high temperature in different atmospheres. In air, Eu~(3+) exists in the form of hexagonal EuOF, in nitrogen, in the form of orthogonal EuF_3 and non-hexagon EuOF. This is because decomposition or disproportionation of EuF_2 is different with different atmospheres. The magnetic susceptibility measurement showed quantitatively that the change rate from Eu~(2+) to Eu~(3+) is about 95% in air, and about 75% in nitrogen when it is heated to 900℃. A small amount of Eu~(2+) coexists with Eu~(3+) in the final product.
The dynamic process of the ionic valence changing from Eu 2+ to Eu 3+ in EuF 2 at high temperature has been investigated by ESCA, high, temperature X-ray diffraction, high temperature spectrum, high temperature magnetic Is susceptibility and It has been shown that the formation of Eu ~ (3+) exists in different compounds when EuF_2 is heated to high temperature in different atmospheres. In air, Eu ~ (3+) exists in the form of hexagonal EuOF, in nitrogen , in the form of orthogonal EuF_3 and non-hexagon EuOF. This is because decomposition or disproportionation of EuF_2 is different with different atmospheres. The magnetic susceptibility measurement showed quantitatively that the rate of change from Eu ~ (2+) to Eu ~ (3+ ) is about 95% in air, and about 75% in nitrogen when it is heated to 900 ° C. A small amount of Eu ~ (2+) coexists with Eu ~ (3+) in the final product.