Structural and vibrational study of C-type doped rare earth sesquioxide Yb 2− x Co x O 3

• Published in: Journal of alloys and compounds Vol. 479; no. 1; pp. 594 - 598
• Main Authors: Farhat, L. Ben, Amami, M., Hlil, E.K., Hassen, R. Ben
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2009
• Subjects: C-type sesquioxide; Sol–gel; XRD and Raman sepectroscopy; XRD and Raman sepectroscopy; C-type sesquioxide; Sol–gel
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2009.01.007

Polycrystalline samples with general formula Yb 2− x Co x O 3 (0 < x < 0.6), obtained by sol–gel method and analysed by X-ray diffraction, formed solid solutions over all the mentioned range. Co showed a maximum solubility of 30 mol% in Yb 2O 3 sesquioxide. The lattice parameters are found to vary linearly with the composition x. The cationic distribution over the two non-equivalent sites 8b and 24d of the space group Ia−3 is found to be preferentially. Replacing Yb 3+ by Co 3+ introduces slight changes in the atomic coordinates leading to an increase of the mean cation–anion distances. The ability of Raman spectroscopy to detect changes in local co-ordination is utilized. A pseudo-tetrahedral coordination for the Co 3+ in the 24d site was found.