Maximizing Exchange Bias in Co/CoO Core/Shell Nanoparticles by Lattice Matching between the Shell and the Embedding Matrix

The exchange bias properties of 5 nm Co/CoO ferromagnetic/antiferromagnetic core/shell nanoparticles, highly dispersed in a CuO matrix, have been optimized by matching the lattice parameter of the matrix with that of the CoO shell. Exchange bias and coercivity fields as large as H = 7780 Oe and H =...

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Detalles Bibliográficos
Autores: Gonzalez, Juan Antonio|||0000-0002-2091-0381, Andrés González, Juan Pedro|||0000-0001-9348-0661, López Antón, Ricardo, De Toro, José A.|||0000-0002-9075-1697, Normile, Peter S., Muñiz, Pablo, Riveiro, J. Manuel, Nogués, Josep|||0000-0003-4616-1371
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:214194
Acceso en línea:https://ddd.uab.cat/record/214194
https://dx.doi.org/urn:doi:10.1021/acs.chemmater.7b00868
Access Level:acceso abierto
Palabra clave:Coercivity field
Core/shell nanoparticles
Dual role
Embedding matrices
Exchange bias
Exchange bias effects
Large amounts
Lattice matching
Descripción
Sumario:The exchange bias properties of 5 nm Co/CoO ferromagnetic/antiferromagnetic core/shell nanoparticles, highly dispersed in a CuO matrix, have been optimized by matching the lattice parameter of the matrix with that of the CoO shell. Exchange bias and coercivity fields as large as H = 7780 Oe and H = 6950 Oe are linked to the presence of a CuO matrix (0.3% lattice mismatch with respect to the shells). The small mismatch between CuO and CoO plays a dual role: it (i) structurally stabilizes the CoO and (ii) favors the existence of a large amount of uncompensated moments in the shell that enhance the exchange bias effects. The results indicate that lattice matching may be a very efficient way to improve the exchange bias properties of core/shell nanoparticles, paving the way to novel approaches to tune their magnetic properties.