Crystal and magnetic structure of the (trimim)[FeBr4] molten salt: a temperature dependence study
A new imidazolium-based halometallate complex with formula (trimim)[FeBr4] (trimim: 1,2,3- trimethylimidazolium) has been synthesized and characterized as a function of the temperature. The structural phase transitions, magnetic properties and magnetic structure of this compound have been thoroughly...
| Autores: | , , , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Recursos: | Universidad de Cantabria (UC) |
| Repositorio: | UCrea Repositorio Abierto de la Universidad de Cantabria |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unican.es:10902/24118 |
| Acesso em linha: | http://hdl.handle.net/10902/24118 |
| Access Level: | acceso abierto |
| Palavra-chave: | Crystal and magnetic structure Halometallate molten salt Magneto-structural correlations Three-dimensional magnetic ordering |
| Resumo: | A new imidazolium-based halometallate complex with formula (trimim)[FeBr4] (trimim: 1,2,3- trimethylimidazolium) has been synthesized and characterized as a function of the temperature. The structural phase transitions, magnetic properties and magnetic structure of this compound have been thoroughly studied. The crystal structure evolution from 1.8 to 400 K has been investigated by a combination of synchrotron X-ray and neutron powder diffraction, as well as single crystal X-ray and neutron diffraction. Four different phases were found: phase I, from 400 to 350 K, with the orthorhombic Cmc21 space group; phase II, from 350 to 160 K,whichwasmodelledwith themonoclinic P21/mspace group; and phase III, stable down to 13 K and showing the monoclinic Cm space group. The transition from phase III to II involves the appearance of disorder in the organic cations.Magnetometry measurements indicate a long-range magnetic order below13 K, whichwas confirmed by single crystal and powder neutron X-ray diffraction analyses. The occurrence of new reflections that were not possible to index with the phase III unit cell suggests a symmetry breaking, giving rise to the phase IV. A joint refinement (single-crystal and powder data) revealed that the latter phase exhibits the magnetic Shubnikov Ccc space group. Thismodel consists of a strictly antiferromagnetic structure with ferromagnetic interactions within the unit cell, which is compatible with the magnetometry results. |
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