Defect-Engineering by Solvent Mediated Mild Oxidation as a Tool to Induce Exchange Bias in Metal Doped Ferrites.

Autor: Muzzi B; Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, I-53100, Italy.; Istituto di Chimica dei Composti Organometallici (ICCOM), Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino (FI), I-50019, Italy.; Department of Chemistry 'U. Schiff', University of Florence and INSTM, Sesto Fiorentino, (FI), I-50019, Italy., Albino M; Department of Chemistry 'U. Schiff', University of Florence and INSTM, Sesto Fiorentino, (FI), I-50019, Italy., Petrecca M; Department of Chemistry 'U. Schiff', University of Florence and INSTM, Sesto Fiorentino, (FI), I-50019, Italy., Innocenti C; Istituto di Chimica dei Composti Organometallici (ICCOM), Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino (FI), I-50019, Italy.; Department of Chemistry 'U. Schiff', University of Florence and INSTM, Sesto Fiorentino, (FI), I-50019, Italy., de Julián Fernández C; Istituto dei Materiali per l' Elettronica ed il Magnetismo (IMEM), Consiglio Nazionale delle Ricerche(CNR), Parma, I-43124, Italy., Bertoni G; CNR - Istituto Nanoscienze, Modena, I-41125, Italy., Ibarra MR; Instituto de Nanociencia y Materiales de Aragón (INMA), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Zaragoza, Zaragoza, 50009, Spain.; Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, 50009, Spain.; Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, Zaragoza, 50009, Spain., Christensen M; Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C, DK-8000, Denmark., Avdeev M; Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW, 2234, Australia.; School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia., Marquina C; Instituto de Nanociencia y Materiales de Aragón (INMA), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Zaragoza, Zaragoza, 50009, Spain.; Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, 50009, Spain., Sangregorio C; Istituto di Chimica dei Composti Organometallici (ICCOM), Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino (FI), I-50019, Italy.; Department of Chemistry 'U. Schiff', University of Florence and INSTM, Sesto Fiorentino, (FI), I-50019, Italy.
Jazyk: angličtina
Zdroj: Small methods [Small Methods] 2023 Nov; Vol. 7 (11), pp. e2300647. Date of Electronic Publication: 2023 Aug 30.
DOI: 10.1002/smtd.202300647
Abstrakt: The crystal site occupancy of different divalent ions and the induction of lattice defects represent an additional tool for modifying the intrinsic magnetic properties of spinel ferrites nanoparticles. Here, the relevance of the lattice defects is demonstrated in the appearance of exchange-bias and in the improvement of the magnetic properties of doped ferrites of 20 nm, obtained from the mild oxidation of core@shell (wüstite@ferrite) nanoparticles. Three types of nanoparticles (Fe0 .95 O@Fe 3 O 4 , Co 0.3 Fe 0.7 O@Co 0.8 Fe 2.2 O 4 and Ni 0.17 Co 0.21 Fe 0.62 O@Ni 0.4 Co 0.3 Fe 2.3 O 4 ) are oxidized. As a result, the core@shell morphology is removed and transformed in a spinel-like nanoparticle, through a topotactic transformation. This study shows that most of the induced defects in these nanoparticles and their magnetic properties are driven by the inability of the Co (II) ions at the octahedral sites to migrate to tetrahedral sites, at the chosen mild oxidation temperature. In addition, the appearance of crystal defects and antiphase boundaries improves the magnetic properties of the starting compounds and leads to the appearance of exchange bias at room temperature. These results highlight the validity of the proposed method to impose novel magnetic characteristics in the technologically relevant class of nanomaterials such as spinel ferrites, expanding their potential exploitation in several application fields.
(© 2023 The Authors. Small Methods published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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