New insight into the plastic deformation mechanisms during the SiO2 phase transition process

• Published in: RSC advances 2024-02, Vol.14 (9), p.6262-6269
• Main Authors: Zhenlun Wei, Li, Yubiao, Li, Peiyue, Pan, Li, Li, Wanqing, Hu, Xianglin, Gu, Yunxiang
• Format: Article
• Language: English
• Subjects: Acid leaching; Chemistry; Cristobalite; Deformation mechanisms; Density functional theory; Evolution; High temperature; Interstitial impurities; Low temperature; Phase transitions; Plastic deformation; Quartz; Roasting; Silicon dioxide
• ISSN: 2046-2069
• DOI: 10.1039/d3ra07633d

The removal of lattice impurities is the key to the purification of high-purity quartz (HPQ), especially for the intracell lattice impurities. Generally, the intracell lattice impurities can be migrated to the quartz surface via roasting, then removed by acid leaching. In order to reveal the phase transition of quartz during the roasting process, the evolution of structure, bond length, volume, lattice parameter and lattice stress in original, Ti4+, Al3+/Li+ and 4H+ substituted SiO2 phases were employed to investigate the mechanisms of plastic deformation based on density functional theory calculations. Results showed that the evolution of bond lengths and volumes were mainly dominated by phase transition, and the interstitial volume in high temperature SiO2 phases was higher than that in low temperature, indicating that the phase transition from α-quartz to β-cristobalite was beneficial to the migration of interstitial impurities. In addition, the phase transition from α-quartz to β-cristobalite needs to overcome the energy barriers while the phase transition from α-cristobalite to β-cristobalite needs to overcome the lattice stress. This study therefore provides an excellent theoretical basis for the plastic deformation mechanism, for the first time, beneficial to understanding the removal mechanisms of lattice impurities.