Atomistic insight into the structure and diffusion properties of pollucite glass-ceramics. Issue 8 (15th April 2022)

• Record Type: Journal Article
• Authors: Yang, Hualong; Ma, Siqi; Duan, Wenjiu; Zhao, Shengjian; Wang, Qikun; Liu, Xuehui; Jiang, Yuqi; He, Peigang; Duan, Xiaoming; Jia, Dechang; Zhou, Yu
• Is Part Of: Ceramics international. Volume 48:Issue 8(2022)
• Page Start: 11134
• Page End: 11144
• Publication Date: 2022-04-15
• Subjects: Pollucite -- Glass-ceramic -- Diffusion -- Molecular simulation; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.12.333
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Molecular dynamics simulations have been performed with an aim to better understand the structure and ion diffusion properties of pollucite glass-ceramics with alkali metal cations dopants. The minor-radius alkali metal cations influence the resistance of volume deformation but have little effect on that of shear deformation. Compared to pollucite, the bond length and bond angle distributions of glass exhibit a broadening characteristic, and the alkali metal cation type would not affect the local environment of Si/Al. It is found that the self-diffusion coefficient of Cs cations in glass phase is lower than the ones of minor-radius alkali metal cations and is reduced as Na/Li is introduced. In comparison, the self-diffusion coefficient of Cs in pollucite is near zero, and the migration energy barrier of Cs cation obtained from metadynamics simulation reaches up to 124.0 kJ/mol, indicating that pollucite is a kind of excellent immobilization candidate material for radioactive Cs.