Direct evidence of a graded magnetic interface in bimagnetic core/shell nanoparticles using electron magnetic circular dichroism (EMCD)

Pozo Bueno, Daniel del; Varela, María; Estrader, Marta; López Ortega, Alberto; Gómez Roca, Alejando; Nogués, Josep; Peiró, Francesca; Estradé, Sònia

Publication:
Direct evidence of a graded magnetic interface in bimagnetic core/shell nanoparticles using electron magnetic circular dichroism (EMCD)

dc.contributor.author	Pozo Bueno, Daniel del
dc.contributor.author	Varela, María
dc.contributor.author	Estrader, Marta
dc.contributor.author	López Ortega, Alberto
dc.contributor.author	Gómez Roca, Alejando
dc.contributor.author	Nogués, Josep
dc.contributor.author	Peiró, Francesca
dc.contributor.author	Estradé, Sònia
dc.contributor.department	Zientziak	eu
dc.contributor.department	Institute for Advanced Materials and Mathematics - INAMAT2	en
dc.contributor.department	Ciencias	es_ES
dc.contributor.funder	Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa	es
dc.date.accessioned	2022-01-26T08:35:08Z
dc.date.available	2022-08-26T23:00:11Z
dc.date.issued	2021
dc.description.abstract	Interfaces play a crucial role in composite magnetic materials and particularly in bimagnetic core/shell nanoparticles. However, resolving the microscopic magnetic structure of these nanoparticles is rather complex. Here, we investigate the local magnetization of antiferromagnetic/ferrimagnetic FeO/Fe3O4 core/shell nanocubes by electron magnetic circular dichroism (EMCD). The electron energy-loss spectroscopy (EELS) compositional analysis of the samples shows the presence of an oxidation gradient at the interface between the FeO core and the Fe3O4 shell. The EMCD measurements show that the nanoparticles are composed of four different zones with distinct magnetic moment in a concentric, onion-type, structure. These magnetic areas correlate spatially with the oxidation and composition gradient with the magnetic moment being largest at the surface and decreasing toward the core. The results show that the combination of EELS compositional mapping and EMCD can provide very valuable information on the inner magnetic structure and its correlation to the microstructure of magnetic nanoparticles.	en
dc.description.sponsorship	The authors acknowledge the financial support from the Spanish Minister of Science and Innovation (MICINN) through the projects PID2019-106165GB-C21, PID2019-106165GB-C22, and PID2019-106229RB-I00. They also acknowledge funding from Generalitat de Catalunya through the 2017-SGR-292 and 2017-SGR-776 projects. In addition, research at UCM was supported by MINECO/FEDER MAT2015-66888-C3-3-R and RTI2018-097895-B-C43 grants. ICN2 is funded by the CERCA programme/Generalitat de Catalunya. The ICN2 is supported by the Severo Ochoa Centres of Excellence programme, funded by the Spanish Research Agency (AEI, Grant SEV-2017-0706). M.E. thanks the Spanish MICINN and AEI/FSE for Ramón y Cajal contract (RYC2018-024396-I). A.L.O. acknowledges support from the Universidad Pública de Navarra (Grant PJUPNA2020). STEM-EELS observations carried out at the Centro Nacional de Microscopía Electrónica at Universidad Complutense de Madrid, Spain (ICTS ELECMI).	en
dc.embargo.lift	2022-08-25
dc.embargo.terms	2022-08-25
dc.format.extent	22 p.
dc.format.mimetype	application/pdf	en
dc.identifier.doi	10.1021/acs.nanolett.1c02089
dc.identifier.issn	1530-6992
dc.identifier.uri	https://academica-e.unavarra.es/handle/2454/41951
dc.language.iso	eng	en
dc.publisher	ACS
dc.relation.ispartof	Nano Letters, 21 (16), 6923-6930	en
dc.relation.projectID	info:eu-repo/grantAgreement/MINECO//MAT2015-66888-C3-3-R/ES/	en
dc.relation.projectID	info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-106165GB-C21/ES/	en
dc.relation.projectID	info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-106165GB-C22/ES/	en
dc.relation.projectID	info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-106229RB-I00/ES/	en
dc.relation.projectID	info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/RTI2018-097895-B-C43/ES/	en
dc.relation.publisherversion	https://doi.org/10.1021/acs.nanolett.1c02089
dc.rights	© 2021 The Authors. Published by American Chemical Society.	en
dc.rights.accessRights	info:eu-repo/semantics/openAccess
dc.subject	Core/shell nanoparticles	en
dc.subject	EELS	en
dc.subject	EMCD	en
dc.subject	Graded interfaces	en
dc.subject	Magnetic nanoparticles	en
dc.title	Direct evidence of a graded magnetic interface in bimagnetic core/shell nanoparticles using electron magnetic circular dichroism (EMCD)	en
dc.type	info:eu-repo/semantics/article
dc.type.version	info:eu-repo/semantics/acceptedVersion	en
dc.type.version	Versión aceptada / Onetsi den bertsioa	es
dspace.entity.type	Publication
relation.isAuthorOfPublication	c295cba6-cd13-4ee7-accd-0a1d5266c972
relation.isAuthorOfPublication.latestForDiscovery	c295cba6-cd13-4ee7-accd-0a1d5266c972