Тип публикации: статья из журнала
Год издания: 2017
Идентификатор DOI: 10.1016/j.jallcom.2017.07.081
Ключевые слова: Al2O3, Ferromagnetic nanocomposite films, Reactive films, Thermite reactions
Аннотация: We have synthesized ferromagnetic nanocomposite Co-Al2O3 thin films via a thermite reaction between Al and Co3O4 with layer geometry. The starting Al/Co3O4 bilayers were obtained by the deposition of Al layers onto Co3O4 films at room temperature and were annealed at temperatures between 50 and 700 °C at 50 °C intervals. Above ∼450Показать полностью°C the Co3O4 partially transformed into the CoO phase. The simultaneous solid-state reactions of Al with Co3O4 and Al with CoO started above the initiation temperature Tin ∼500 °C, which did not depend on the bilayer thickness. After annealing at 700 °C about 60% of the Co was reduced by the Al and the rest of the Co was contained in intermediate CoAl2O4 shells, which separated the Co nanoparticles from the Al2O3 matrix. Above 700 °C the reaction was complete and the final products were noninteracting Co nanoparticles with an average size of ∼40 nm enveloped by CoAl2O4 shells, which embedded into a dielectric Al2O3 matrix. The synthesized Co-Al2O3 nanocomposite films possessed soft magnetic behavior and good chemical stability.
Журнал: Journal of Alloys and Compounds
Выпуск журнала: Т. 724
Номера страниц: 820-826
ISSN журнала: 09258388
Издатель: Elsevier Science Publishing Company, Inc.