Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2021

Идентификатор DOI: 10.1016/j.jallcom.2020.156753

Ключевые слова: ferrihydrite, core-shell nanoparticles, superparamagnetism, surface magnetic anisotropy

Аннотация: Ferrihydrite is a low-crystalline nanoscale matter. The uncompensated magnetic moment of the ferrihydrite caused by the antiferromagnetic ordering of the magnetic moments of iron atoms and leads to the magnetic properties very similar to those of ferro- and ferrimagnetic nanoparticles. In this study, we investigated the biogenic ferrihydrite nanoparticles with the narrow size distribution and an average diameter of 2 nm obtained by the bacteria life cycle. The features caused by the surface effects and the inhomogeneous structure of ferrihydrite have been examined in the temperature range of 4-300 K using Mossbauer spectroscopy and magnetometry. Based on the Mossbauer data, we identified the superparamagnetic blocking temperature at the temperature of 30 K for the largest ferryhidrite particles. We established that the exceptional magnetic anisotropy of ferrihydrite (K-v = 1.2.10(5) erg/cm(3) and K-s = 0.1 erg/cm(2)) is reached because of the highly developed ferrihydrite nanoparticles' surface. According to the Mossbauer data, we propose a core-shell structural model of the biogenic ferrihydrite particles. We found that the size of the dense core depends on the particle size. The well-crystallized core is formed only for nanoparticles larger than approximate to 2 nm, whereas smaller particles consist entirely of a matter with a lower density of iron atoms.(C) 2020 Elsevier B.V. All rights reserved.

Журнал: JOURNAL OF ALLOYS AND COMPOUNDS

Выпуск журнала: Vol. 851

Номера страниц: 156753

ISSN журнала: 09258388

Место издания: LAUSANNE

Издатель: ELSEVIER SCIENCE SA

• Knyazev Yu (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Akademgorodok 50,Bld 38, Krasnoyarsk 660036, Russia)
• Balaev D.A. (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Akademgorodok 50,Bld 38, Krasnoyarsk 660036, Russia; Siberian Fed Univ, Svobodniy 79, Krasnoyarsk 660041, Russia)
• Stolyar S.V (Siberian Fed Univ, Svobodniy 79, Krasnoyarsk 660041, Russia; Fed Res Ctr KSC SB RAS, Krasnoyarsk Sci Ctr, Akademgorodok 50, Krasnoyarsk 660036, Russia)
• Bayukov O.A. (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Akademgorodok 50,Bld 38, Krasnoyarsk 660036, Russia)
• Yaroslavtsev R.N. (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Akademgorodok 50,Bld 38, Krasnoyarsk 660036, Russia; Fed Res Ctr KSC SB RAS, Krasnoyarsk Sci Ctr, Akademgorodok 50, Krasnoyarsk 660036, Russia)
• Ladygina V.P. (Siberian Fed Univ, Svobodniy 79, Krasnoyarsk 660041, Russia)
• Velikanov D.A. (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Akademgorodok 50,Bld 38, Krasnoyarsk 660036, Russia)
• Iskhakov R.S. (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Akademgorodok 50,Bld 38, Krasnoyarsk 660036, Russia)

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