A comparison of oxygen Frenkel formation and rare earth doping in the Lu2SiO5 and Y2SiO5 orthosilicates using a computer modelling approach

de S. Santos, Anderson L.; B. V. Freire, Eduily; da C. Bispo, Giordano F.; Jackson, Robert. A.; Macedo, Zélia S.; E. G. Valerio, Mário

Abstract

The Lu2SiO5 (LSO) and Y2SiO5 (YSO) orthosilicates are well-known in the literature for their properties when doped with rare earth ions. Ce-doped LSO and YSO hosts have been considered as scintillators with high efficiency, but some questions about the of effect of the intrinsic defects in the luminescence yield of such scintillators are still open. In this work, static and classical atomistic computer modelling techniques were applied to study the cases of RE3+ doping in LSO and YSO hosts as well as the probability that intrinsic defects may be formed close to the dopant. The approach used was based on the model of interatomic potentials and the lattice energy minimization method. Results show that isovalent substitution in the RE sites was the most favourable due to the similarity of the ions. In LSO, dopants present a preference for Lu1 (coordination number: 8) substitution rather than Lu2 (coordination number: 7), while for YSO there is a clear dependence of the main type of defect with the ionic radius of the dopant as compared to the Y3+ size. The presence of a closer oxygen Frenkel pair (O2– vacancy plus interstitial O2– ion) was tested in different configurations. The analyses showed that presence of RE3+ dopants in the LSO orthosilicate favours the formation of oxygen Frenkel defects at distances smaller than 7 Å for all dopants except Ce3+, whereas only some dopants can stabilize the Frenkel pair in the YSO system.

Citation

de S. Santos, A. L., B. V. Freire, E., da C. Bispo, G. F., Jackson, R. A., Macedo, Z. S., & E. G. Valerio, M. (2024). A comparison of oxygen Frenkel formation and rare earth doping in the Lu2SiO5 and Y2SiO5 orthosilicates using a computer modelling approach. Computational Materials Science, 243, Article 113125. https://doi.org/10.1016/j.commatsci.2024.113125

• Journal Article Type: Article
• Acceptance Date: May 22, 2024
• Online Publication Date: May 29, 2024
• Publication Date: 2024-07
• Deposit Date: Aug 8, 2024
• Publicly Available Date: May 30, 2026
• Journal: Computational Materials Science
• Print ISSN: 0927-0256
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 243
• Article Number: 113125
• DOI: https://doi.org/10.1016/j.commatsci.2024.113125
• Public URL: https://keele-repository.worktribe.com/output/876475
• Additional Information: This article is maintained by: Elsevier; Article Title: A comparison of oxygen Frenkel formation and rare earth doping in the Lu2SiO5 and Y2SiO5 orthosilicates using a computer modelling approach; Journal Title: Computational Materials Science; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.commatsci.2024.113125; Content Type: article; Copyright: © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.