Physical Review B 79, 241106 (2009)

Color shift in Al₂O₃.xCr₂O₃ solid solutions and the electroneutrality principle

J.M García-Lastra, M.T. Barriuso, J.A. Aramburu, M.Moreno

Although the series of Al₂O₃. xCr₂O₃ compounds is a model system among mixed crystals the actual origin of the progressive color change from red to green upon increasing the chromium content is not clarified yet. It is shown in this work that such a color shift for x < 0.2 mainly comes from the reduction of the internal electric field, experienced by the CrO₆^9- complex, due to the progressive replacement of a close Al³⁺ ion by Cr³⁺ as a result of the electroneutrality principle. The proposed model accounts for the color shift along the whole series.

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http://dx.doi.org/10.1103/PhysRevB.79.241106

Related Research Areas

• Extended systems: solids, surfaces, liquids. Applications (e.g photovoltaics)