Magnetic chains of Fe3 clusters in the {Fe3YO2} butterfly molecular compound
| Autor: | Fernando Bartolomé, Fernando Luis, Denis Prodius, Valeriu Mereacre, Javier Rubín, L. Badía-Romano, Ana B. Arauzo, Juan Bartolomé |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission |
| Rok vydání: | 2020 |
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| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | The “butterfly” molecule [Fe3Y(μ3-O)2(CCl3COO)8(H2O)(THF)3] (in brief {Fe3YO2}) includes three Fe3+ ions which build a robust Fe3 cluster with a strong intracluster antiferromagnetic exchange Image ID:c9dt04816b-t1.gif and a total spin S = 5/2. It represents the starting magnetic system to study further interactions with magnetic rare earths when Y is replaced with lanthanides. We present heat capacity and equilibrium susceptibility measurements below 2 K, which show that each cluster has a sizeable magnetic anisotropy pointing to the existence of intercluster interactions. However, no phase transition to a long-range magnetically ordered phase is observed down to 20 mK. The intercluster interaction is analysed in the framework of the one-dimensional Blume–Capel model with an antiferromagnetic chain interaction constant J/kB = −40(2) mK between Fe3 cluster spins, and a uniaxial anisotropy with parameter D/kB = −0.56(3) K. This is associated to single chains of Fe3 clusters oriented along the shortest intercluster distances displayed by the crystal structure of {Fe3YO2}. Ac susceptibility measurements reveal that the magnetic relaxation is dominated by a quantum tunnelling process below 0.2 K, and by thermally activated processes above this temperature. The experimental activation energy of this single chain magnet, Ea/kB = 3.4(6) K, can be accounted for by the combination of contributions arising from single-molecule magnetic anisotropy and spin–spin correlations along the chains. We acknowledge financial support from the MCINN projects MAT2017-83468-R, RTI2018-096075-B-C21 and PCI2018-093116, as well as COST Action on Molecular Spintronics (CA15128, MOLSPIN). The authors would like to acknowledge the use of the Servicio General de Apoyo a la Investigación-SAI, Universidad de Zaragoza, and Aragonese E12_17R RASMIA and E09_17R Q-MAD (co-funded by Fondo Social Europeo), and of the European Union FEDER (ES). |
| Databáze: | OpenAIRE |
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