ABSORPTION SPECTRUM OF $Cu^{2+}$ IN DIFFERENT COORDINATIONS

Abstract

“The absorption spectrum of $Cu^{2+}$ has been studied in $CuSiF_{6} \bullet 6H_{2}O$, in a copper doped ZnO single crystal and in a Cu doped single crystal of YGG. From the absorption spectrum of $CuSiF_{6} \bullet 6H_{2}O$, the crystal field parameter for $Cu^{2+}$ in octahedral coordination is deduced and used to predict the energy levels of $Cu^{2+}$ in tetrahedral coordination according to the relation $Dq_{(tet)} = -\frac{4}{9} Dq_{(oct)}$. The accuracy of the prediction is excellent. A series of sharp intense lines is found at $5900 cm^{-1}$ for Cu in ZnO. The results are used to interpret the absorption of Cu in YGG where there is considerable evidence that $Cu^{2+}$ is present in a tetrahedral site.”