Size Effects in the Magnetic Properties of ε-Fe2O3 Nanoparticles Научная публикация
| Журнал |
Journal of Applied Physics
ISSN: 0021-8979 , E-ISSN: 1089-7550 |
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| Вых. Данные | Год: 2015, Том: 118, Номер статьи : 213901, Страниц : 12 DOI: 10.1063/1.4936838 | ||||||||||
| Ключевые слова | Anisotropy; Crystallography; High resolution electron microscopy; Magnetic anisotropy; Magnetic properties; Magnetic resonance measurement; Magnetic variables measurement; Magnetism; Mossbauer spectroscopy; Nanomagnetics; Nanoparticles; Particle size | ||||||||||
| Авторы |
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| Организации |
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Информация о финансировании (2)
| 1 | Федеральное агентство научных организаций России | V.44.1.15. |
| 2 | Новосибирский национальный исследовательский государственный университет |
Реферат:
We report the results of comparative analysis of magnetic properties of the systems based on ε-Fe2O3, nanoparticles with different average sizes (from ∼3 to 9 nm) and dispersions. The experimental data for nanoparticles higher than 6–8 nm in size are consistent with the available data, specifically, the transition to the magnetically ordered state occurs at a temperature of ∼500 K and the anomalies of magnetic properties observed in the range of 80–150 K correspond to the magnetic transition. At the same time, Mőssbauer and ferromagnetic resonance spectroscopy data as well as the results of static magnetic measurements show that at room temperature all the investigated samples contain ε-Fe2O3 particles that exhibit the superparamagnetic behavior. It was established that the magnetic properties of nanoparticles significantly change with a decrease in their size to ∼6 nm. According to high-resolution electron microscopy and Mőssbauer spectroscopy data, the particle structure can be attributed to the ε–modification of trivalent iron oxide; meanwhile, the temperature of the magnetic order onset in these particles is increased, the well-known magnetic transition in the range of 80–150 K does not occur, the crystallographic magnetic anisotropy constant is significantly reduced, and the surfacemagnetic anisotropy plays a decisive role. This is apparently due to redistribution of cations over crystallographic positions with decreasing particle size, which was established using Mössbauer spectra. As the particle size is decreased and the fraction of surface atoms is increased, the contribution of an additional magnetic subsystem formed in a shell of particles smaller than ∼4 nm becomes significant, which manifests itself in the static magnetic measurements as paramagnetic contribution.
Библиографическая ссылка:
Dubrovskiy A.A.
, Balaev D.A.
, Shaykhutdinov K.A.
, Bayukov O.A.
, Pletnev O.N.
, Yakushkin S.S.
, Bukhtiyarova G.A.
, Martyanov O.N.
Size Effects in the Magnetic Properties of ε-Fe2O3 Nanoparticles
Journal of Applied Physics. 2015. V.118. 213901 :1-12. DOI: 10.1063/1.4936838 WOS Scopus РИНЦ CAPlusCA OpenAlex
Size Effects in the Magnetic Properties of ε-Fe2O3 Nanoparticles
Journal of Applied Physics. 2015. V.118. 213901 :1-12. DOI: 10.1063/1.4936838 WOS Scopus РИНЦ CAPlusCA OpenAlex
Даты:
| Поступила в редакцию: | 15 июл. 2015 г. |
| Принята к публикации: | 18 нояб. 2015 г. |
| Опубликована online: | 1 дек. 2015 г. |
| Опубликована в печати: | 7 дек. 2015 г. |
Идентификаторы БД:
| Web of science: | WOS:000369918100009 |
| Scopus: | 2-s2.0-84949009026 |
| РИНЦ: | 26734287 |
| Chemical Abstracts: | 2015:1935480 |
| Chemical Abstracts (print): | 164:65145 |
| OpenAlex: | W2182509619 |