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В. П. Іваницький, О. Б. Брик, Н. О. Дудченко, Е. В. Польшин, Я. В. Редько
«Зміна фазового складу синтетичних магнетовпорядкованих наночастинок оксидів і гідроксидів заліза з різними покриттями за даними Мессбауерової спектроскопії»
109–118 (2013)

PACS numbers: 61.05.Qr, 75.75.Cd, 76.80.+y, 81.07.Bc, 81.16.-c, 87.64.kx, 87.80.Dj

Phase composition of synthesized magnetically ordered nanoparticles with biocompatible coverings and the process of their ‘ageing’ after storage under environmental conditions during 2.5 years are studied by means of the 57Fe M?ssbauer spectroscopy. As found, the phases coexisting in nanoparticles are magnetite, maghemite and goethite. Each sample has individual phase composition. As determined, the ‘ageing’ of nanoparticles appears in oxidation of magnetite that is a dominant phase and in formation of separate phase—maghemite. Goethite formation is not observed, during the process of samples’ ‘ageing’, but its quantity increase insignificantly in ‘aged’ samples as compared to initial samples. The cause of magnetite oxidation could be excess oxygen ions, hydroxyl groups and chemically bounded water, which could be the result of nanoparticles’ synthesis by precipitation method. The covering of developed high-imperfect surface of nanoparticles by biocompatible materials does not eliminate the possibility of diffusion of oxidants from environment. Obtained results could be used for improvement of synthesis technologies of environmentally stable magnetically ordered nanoparticles with predetermined properties.