Crystallization process of transparent conductive oxides Zn(k)In2O(k+3).

Crystallization process of the homologous compounds Zn(k)In2O(k+3) from the coprecipitants was examined by XAFS spectroscopy and X ray diffractometry. Interesting crystallization behavior could be observed. Though zinc oxide already crystallized as the wurtzite-type ZnO at 573K, indium oxide remained amorphous. Subsequently bixbyite-type In2O3 appeared at 873K for k=5 and 7 and at below 773K for the other k-members, respectively. The InO distance in the amorphous In2O3 was a little shorted than that in the bixbyite-type In2O3 by 0.06-7A. The distance remained constant but abruptly increased to that observed in the bixbyite-type In2O3 in accordance with the progress of crystallization. Then the distance gradually decreased and converged to ca. 2.12A at the temperature range of 1173-1373K, due to the reaction between In2O3 and ZnO to form the homologous compound.