Interfaceless Exchange Bias in CoFe2O4 Nanocrystals

被引：17

作者：

Rivas-Murias, Beatriz ^{[1
]}

Testa-Anta, Martin ^{[2
]}

Skorikov, Alexander S. ^{[3
]}

Comesana-Hermo, Miguel ^{[4
]}

Bals, Sara ^{[3
]}

Salgueirino, Veronica

机构：

[1] Univ Vigo, CACTI, Vigo 36310, Spain

[2] Inst Ciencia Mat Barcelona ICMAB CSIC, Bellaterra 08193, Spain

[3] Univ Antwerp, Electron Microscopy Mat Res EMAT, B-2020 Antwerp, Belgium

[4] Univ Paris Cite, CNRS, ITODYS, F-75013 Paris, France

来源：

NANO LETTERS | 2023年 / 23卷 / 05期

基金：

欧洲研究理事会;

关键词：

Exchange bias; spinel ferrite nanocrystals; pinned and unpinned uncompensated moments; Raman spectroscopy; MAGNETIC-PROPERTIES; RAMAN-SPECTROSCOPY; PARTICLE-SIZE; COBALT; NANOPARTICLES; OXIDATION; NANOCUBES; MN; CO;

D O I：

10.1021/acs.nanolett.2c04268

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Oxidized cobalt ferrite nanocrystals with a modified distribution of the magnetic cations in their spinel structure give place to an unusual exchange-coupled system with a double reversal of the magnetization, exchange bias, and increased coercivity, but without the presence of a clear physical interface that delimits two well-differentiated magnetic phases. More specifically, the partial oxidation of cobalt cations and the formation of Fe vacancies at the surface region entail the formation of a cobalt-rich mixed ferrite spinel, which is strongly pinned by the ferrimagnetic background from the cobalt ferrite lattice. This particular configuration of exchange-biased magnetic behavior, involving two different magnetic phases but without the occurrence of a crystallographically coherent interface, revolu-tionizes the established concept of exchange bias phenomenology.

引用

页码：1688 / 1695

页数：8