Controlling multiple orderings in metal thiocyanate molecular perovskites Ax{Ni[Bi(SCN)6]}

Lee, Jie Yie; Ling, Sanliang; Argent, Stephen; Senn, Mark; Ca�adillas-Delgado, Laura; Cliffe, Matthew

Abstract

We report four new A-site vacancy ordered thiocyanate double double perovskites, A1–x{Ni[Bi(SCN)6](1–x)/3}, A = K+, NH4+, CH3(NH3)+ (MeNH3+) and C(NH2)3+ (Gua+), including the first examples of thiocyanate perovskites containing organic A-site cations. We show, using a combination of X-ray and neutron diffraction, that the structure of these frameworks depends on the A-site cation, and that these frameworks possess complex vacancy-ordering patterns and cooperative octahedral tilts distinctly different from atomic perovskites. Density functional theory calculations uncover the energetic origin of these complex orders and allow us to propose a simple rule to predict favoured A-site cation orderings for a given tilt sequence. We use these insights, in combination with symmetry mode analyses, to show that these complex orders offer a new route to non-centrosymmetric perovskites which render them as excellent candidates for piezo- and ferroelectric applications.

Citation

Lee, J. Y., Ling, S., Argent, S., Senn, M., Cañadillas-Delgado, L., & Cliffe, M. (2021). Controlling multiple orderings in metal thiocyanate molecular perovskites Ax{Ni[Bi(SCN)6]}. Chemical Science, 12(10), 3516-3525. https://doi.org/10.1039/d0sc06619b

• Journal Article Type: Article
• Acceptance Date: Jan 15, 2021
• Online Publication Date: Jan 15, 2021
• Publication Date: Mar 14, 2021
• Deposit Date: Jan 15, 2021
• Publicly Available Date: Jan 18, 2021
• Journal: Chemical Science
• Print ISSN: 2041-6520
• Electronic ISSN: 2041-6539
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 10
• Pages: 3516-3525
• DOI: https://doi.org/10.1039/d0sc06619b
• Keywords: General Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/5228967
• Publisher URL: https://pubs.rsc.org/en/Content/ArticleLanding/2021/SC/D0SC06619B#!divAbstract