Spin-Phonon Coupling and Slow-Magnetic Relaxation in Pristine Ferrocenium
| Autor: | Eliseo Ruiz, Lindley Maxwell, Martín Amoza, Silvia Gómez-Coca, Núria Aliaga-Alcalde |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Aliaga Alcalde, Nuria [0000-0003-1080-3862], Gómez-Coca, Silvia [0000-0002-2299-4697], Ruiz, Eliseo [0000-0001-9097-8499], Aliaga Alcalde, Nuria, Gómez-Coca, Silvia, Ruiz, Eliseo |
| Rok vydání: | 2021 |
| Předmět: |
Spin-phonon coupling
Coupling constant Fonons Propietats magnètiques Metallocenes Phonon Ferromagnetisme Organic Chemistry General Chemistry Spin dynamics Molecular physics Catalysis chemistry.chemical_compound Magnetic anisotropy chemistry Transition metal Magnetic properties Cobaltocene Ferromagnetism Phonons Condensed Matter::Strongly Correlated Electrons Ab initio calculations Excitation Quantum tunnelling Spin-½ |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1521-3765 |
| Popis: | We report the spin dynamic properties of non-substituted ferrocenium complexes. Ferrocenium shows a field-induced single-molecule magnet behaviour in DMF solution while cobaltocene lacks slow spin relaxation neither in powder nor in solution. Multireference quantum mechanical calculations give a non-Aufbau orbital occupation for ferrocenium with small first excitation energy that agrees with the relatively large measured magnetic anisotropy for a transition metal S=1/2 system. The analysis of the spin relaxation shows an important participation of quantum tunnelling, Raman, direct and local-mode mechanisms which depend on temperature and the external field conditions. The calculation of spin-phonon coupling constants for the vibrational modes shows that the first vibrational mode, despite having a low spin-phonon constant, is the most efficient process for the spin relaxation at low temperatures. In such conditions, vibrational modes with higher spin-phonon coupling constants are not populated. Additionally, the vibrational energy of this first mode is in excellent agreement with the experimental fitted value obtained from the local-mode mechanism. The research reported here was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (grants PGC2018-093863-B-C21, PID2019-108794GB-I00 and centres of excellence MDM-2017-0767 and Severo Ochoa FUNFUTURE (CEX2019-000917-S). E.R. thanks Generalitat de Catalunya for an ICREA Academia award and for the SGR2017-1289 and -1277 grants. S.G.-C. thanks the Generalitat de Catalunya for a Beatriu de Pinòs grant. M.A. acknowledges the Ministerio de Educación, Cultura y Deporte for an FPU predoctoral grant. Authors acknowledge computer resources, technical expertise and assistance provided by the CSUC. We want to thank Prof. Santiago Alvarez for his help with the Shape code. With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S). |
| Databáze: | OpenAIRE |
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