Formation of Cubic Modification Oxides with Type C BCC Lattice in Polycrystalline Dioxides of Hafnium, Zirconium, and Cerium upon Heating
| Autor: | A. E. Solov’eva |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Refractories and Industrial Ceramics. 62:175-184 |
| ISSN: | 1573-9139 1083-4877 |
| DOI: | 10.1007/s11148-021-00579-4 |
| Popis: | In the study of the structural properties of HfO2 and ZrO2 samples with the addition of 5 mol.% In2O3, the following phase transformations were detected when heating the samples in vacuum at temperatures ranging from 25 to 1600°C:M → T → F1 → (F + C). Phase transformations in CeO2 samples with and without the addition of 1 mol.% SrO proceed according to the following sequence: F → F1 → (F + C). These phase transformations were compared with those of the structural analogues, such as CeO2 and from TbO2 to ThO2. For dioxides from HfO2 to ThO2, the ionic radii were determined and their linear dependence on the crystal lattice parameters was established. Alinear dependence of the unit cell parameters on the ionic radii of the cations of Me2O3 type compounds with type C structure (from Sc2O3 to Th2O3) was developed. The C-Ia3 type compounds, such as Hf2O3, Zr2O3, and Ce2O3, were identified, which comply with this linear dependence based on the unit cell parameters and ionic radii of cations. The interplanar distances of the structure and unit cell parameters of both dioxides and oxides of hafnium, zirconium, and cerium are provided. The obtained results confirm the existence of Ce2O3, (Hf,In)2O3, and (Zr,In)2O3 oxides with type C-Ia3 BCC structure of the crystalline lattice. |
| Databáze: | OpenAIRE |
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