The importance of cation–cation repulsion in the zircon–reidite phase transition and radiation-damaged zircon
| Autor: | Akira Yoshiasa, Saki Hashimoto, Seiichiro Uehara, Makoto Tokuda, Masaki Akaogi, Hiroshi Kojitani, Tsutomu Mashimo, Tsubasa Tobase |
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| Rok vydání: | 2019 |
| Předmět: |
Diffraction
Phase transition Materials science Radiation 010502 geochemistry & geophysics 010403 inorganic & nuclear chemistry 01 natural sciences 0104 chemical sciences Dodecahedron Geochemistry and Petrology Chemical physics Lattice (order) Tetrahedron Radioactive decay 0105 earth and related environmental sciences Zircon |
| Zdroj: | Mineralogical Magazine. 83:561-567 |
| ISSN: | 1471-8022 0026-461X |
| DOI: | 10.1180/mgm.2019.27 |
| Popis: | Single crystals of synthetic reidite and natural radiation-damaged zircon from Okueyama, Japan were investigated using X-ray diffraction. The pressure-induced zircon–reidite transition is described by the twisting and translations of SiO4 tetrahedra with disappearance of the SiO4–ZrO8 shared edges. The lattice of radiation-damaged zircons expands mainly from α-decays of radioactive elements such as U and Th. Although old radiation-damaged zircons show anomolous lattice distortion, young radiation-damaged zircons do not show such distortions. These distortions are caused by thermal recovery that suppresses the Si4+–Zr4+ repulsion between the SiO4 tetrahedron and ZrO8 dodecahedron. These changes in structure can be understood by considering the cation–cation repulsion between the SiO4–ZrO8 shared edges. |
| Databáze: | OpenAIRE |
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