Magnetism and Mossbauer study of formation of multi-core γ-Fe2O3 nanoparticles

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:451

Article

Kamali, Saeed¹  Bringas, Eugenio²  Hah, Hien-Yoong¹  Bates, Brian³  Johnson, Jacqueline A.¹  Johnson, Charles E.⁴  Stroeve, Pieter⁵ 

[1] Univ Tennessee, Inst Space, Dept Mech Aerosp & Biomed Engn, Tullahoma, TN 37388 USA

[2] Univ Cantabria, Dept Chem & Biomol Engn, Av Castros S-N, Santander 39005, Cantabria, Spain

[3] Tennessee Technol Univ, Ctr Mfg Res, Cookeville, TN 38505 USA

[4] Univ Tennessee, Inst Space, Ctr Laser Applicat, Tullahoma, TN 37388 USA

[5] Univ Calif Davis, Dept Chem Engn, Davis, CA 95616 USA

关键词: Multi-core-shell nanoparticles;    Maghemite nanoparticles;    Mossbauer spectroscopy;    High-resolution transmission electron microscopy;    Magnetization measurements;    Nanomagnetism;   

DOI  :  10.1016/j.jmmm.2017.10.102

来源: Elsevier

【 摘 要 】

A systematic investigation of magnetic nanoparticles and the formation of a core-shell structure, consisting of multiple maghemite (gamma-Fe2O3) nanoparticles as the core and silica as the shell, has been performed using various techniques. High-resolution transmission electron microscopy clearly shows isolated maghemite nanoparticles with an average diameter of 13 nm and the formation of a core-shell structure. Low temperature Mossbauer spectroscopy reveals the presence of pure maghemite nanoparticles with all vacancies at the B-sites. Isothermal magnetization and zero-field-cooled and field-cooled measurements are used for investigating the magnetic properties of the nanoparticles. The magnetization results are in good accordance with the contents of the magnetic core and the non-magnetic shell. The multiple-core gamma-Fe2O3 nanoparticles show similar behavior to isolated particles of the same size. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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