Analysis of Sm₂Zr₂O₇ forming mechanism by X-ray diffraction

The forming mechanism of Sm₂Zr₂O₇ prepared by solid reaction was studied by X-Ray diffraction method. The results show that the gradual substitution of Sm³⁺ for Zr⁴⁺ site began from 1000°C. and was ended basically up to 1400°C. The solid solution reaction between Sm₂O₃ and ZrO₂ took place in the range of 1200°C-1300°C, resulting in forming Sm₂Zr₂O₇ with pyrochlore structure. The reaction last up to 1500°C, then was ended completely. When the temperature was over 1500°C, Sm₂Zr₂O₇ crystal grew up gradually, and finally an ideal Sm₂Zr₂O₇ crystal was obtained. No other intermediate phases were found in the whole process.