Elastic Modeling of Two-Step Transitions in Sterically Frustrated 1D Binuclear Spin-Crossover Chains
| العنوان: | Elastic Modeling of Two-Step Transitions in Sterically Frustrated 1D Binuclear Spin-Crossover Chains |
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| المؤلفون: | Hassane Oubouchou, Kamel Boukheddaden, Rachid Traiche |
| المصدر: | Symmetry Volume 13 Issue 10 Symmetry, Vol 13, Iss 1836, p 1836 (2021) |
| بيانات النشر: | MDPI AG, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Phase transition, bistability and multistability, Physics and Astronomy (miscellaneous), Spin states, General Mathematics, media_common.quotation_subject, Spin transition, Frustration, Monte Carlo simulations, Ising models, Spin crossover, QA1-939, Computer Science (miscellaneous), 1D elastic chains, media_common, Spin-½, Physics, Intermolecular force, Relaxation (NMR), spin transition, elastic frustration, binuclear, phase transitions, Chemistry (miscellaneous), Chemical physics, Mathematics |
| الوصف: | Among the large family of spin-crossover materials, binuclear systems play an important role due to their specific molecular configurations, allowing the presence of multi-step transitions and elastic frustration. Although this issue benefited from a significant number of spin-based theories, there is almost no elastic description of the spin transition phenomenon in binuclear systems. To overcome this deficiency, in this work we develop the first elastic modeling of thermal properties of binuclear spin-crossover solids. At this end, we investigated a finite spin-crossover open chain constituted of elastically coupled binuclear (A = B) blocks, ⋯A=B−A=B−A=B⋯, in which the considered equivalent A and B sites may occupy two configurations, namely low-spin (LS) and high-spin (HS) states. The sites of the binuclear unit interact via an intramolecular spring and couple to the neighboring binuclear units via other springs. The model also includes the change of length inside and between the binuclear units subsequent to the spin state changes. When injecting an elastic frustration inside the binuclear unit in the LS state, competing interactions between the intra- and the inter-binuclear couplings emerge. The latter shows that according to the intra- and inter-binuclear elastic constants and the strength of the frustration, multi-step transitions are derived, for which a specific self-organization of type (HS = HS)-(LS-LS)-(HS = HS)⋯ is revealed and discussed. Finally, we have also studied the relaxation of the metastable photoinduced HS states at low temperature, in which two relaxation regimes with transient self-organized states were identified when monitoring the elastic frustration rate or the ratio of intra- and intermolecular elastic interactions. These behaviors are reminiscent of the thermal dependence of the order parameters of the system. The present model opens several possibilities of extensions of elastic frustrations acting in polynuclear spin-crossover systems, which may lead to other types of spin-state self-organizations and relaxation dynamics. |
| وصف الملف: | application/pdf |
| تدمد: | 2073-8994 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a6de2a3ad2f1402028a1d1e535016ee7 https://doi.org/10.3390/sym13101836 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....a6de2a3ad2f1402028a1d1e535016ee7 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 20738994 |
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