Dual disorder-driven magnetic dynamics in GdCu2 superantiferromagnetic nanoparticles
The spin dynamics in magnetically disordered GdCu2 nanoparticles, varying the nanoparticle size in the range 53 to 7 nm, has been scrutinized. Dynamic χAC susceptibility measurements have revealed the existence of dissipation at Tg = 18 K, which is associated to the spin freezing transition, for all...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad de Cantabria (UC) |
| Repositorio: | UCrea Repositorio Abierto de la Universidad de Cantabria |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unican.es:10902/28168 |
| Acceso en línea: | https://hdl.handle.net/10902/28168 |
| Access Level: | acceso abierto |
| Palabra clave: | Magnetic nanoparticles Antiferromagnetism Frustrated magnetism Spin dynamics |
| Sumario: | The spin dynamics in magnetically disordered GdCu2 nanoparticles, varying the nanoparticle size in the range 53 to 7 nm, has been scrutinized. Dynamic χAC susceptibility measurements have revealed the existence of dissipation at Tg = 18 K, which is associated to the spin freezing transition, for all the ensembles. Besides, the superantiferromagnetic ensembles (〈D〉≥ 24 nm) also showcase a dissipation contribution close to the vicinity of the Néel transition, TN = 40.2 K. This dissipation, which takes the form of two humps located at Td1 = 33.5(5) K and Td2 = 40.0(5) K, is associated to uncompensated antiferromagnetic moments. Time-dependent phenomena (ageing and memory effects) are only evidenced below the spin freezing transition, evidencing that solely this low-temperature disordered phase is driven by the frustration of RKKY exchange interactions. Consequently, GdCu2 nanoparticles display a dual disorder-driven magnetic dynamics, which are the one ascribed to the magnetically frustrated moments located at the nanoparticle surface; and that of uncompensated antiferromagnetic moments located within the nanoparticle core. |
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