Spin-glass behavior of warwickite MgFeBO4 and CoFeBO4 crystals observed by Mossbauer spectroscopy

Описание

Тип публикации: статья из журнала

Год издания: 2015

Идентификатор DOI: 10.1016/j.jallcom.2015.04.067

Ключевые слова: Warwickites, Spin-glass, Mossbauer spectroscopy, Mossbauer spectroscopy, Spin-glass, Warwickites, Anisotropy, Glass, Glass transition, Magnetic susceptibility, Magnetism, Magnetocrystalline anisotropy, Single crystals, Temperature, Dynamical scaling theory, Magnetic susceptibility measurements, Magnetic transitions, Non-equivalent sites, Spin-freezing temperature, Ssbauer spectroscopies, Superparamagnetic behavior, Warwickites, Spin glass

Аннотация: Single crystals of MgFeBO4 and CoFeBO4 warwickites were obtained. The effects of charge ordering and magnetic properties were investigated by Mossbauer spectroscopy. Cation distribution over M1 and M2 nonequivalent sites and the average charge at the metal positions were established. Low temperature Mossbauer spectra reveal spin-glПоказать полностьюass behavior, with spin-freezing temperatures T-SG of 15.2 and 33.2 K for Mg-and Co-warwickites, respectively, higher than that observed from the d.c. and a.c. magnetic susceptibility measurements. The difference is explained in terms of dynamical scaling theory. The specific shape of the Mossbauer spectra in the vicinity of the magnetic transition at T-SG shows the difference between spin-glass and superparamagnetic behavior and demonstrates an overwhelming role of the exchange anisotropy in the properties of Mg-warwickite. In Co-warwickite the increase of magnetocrystalline anisotropy provokes an increase in magnetic viscosity. (C) 2015 Elsevier B.V. All rights reserved.

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Издание

Журнал: JOURNAL OF ALLOYS AND COMPOUNDS

Выпуск журнала: Vol. 642

Номера страниц: 204-209

ISSN журнала: 09258388

Место издания: LAUSANNE

Издатель: ELSEVIER SCIENCE SA

Авторы

  • Lyubutin I.S. (Shubnikov Institute of Crystallography, RAS)
  • Bartolome J. (Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, Departamento de Fisica de la Materia Condensada)
  • Korotkov N.Y. (Shubnikov Institute of Crystallography, RAS)
  • Frolov K.V. (Shubnikov Institute of Crystallography, RAS)
  • Kazak N.V. (Kirensky Institute of Physics, SB of RAS)
  • Platunov M.S. (Kirensky Institute of Physics, SB of RAS)
  • Bezmaternykh L.N. (Kirensky Institute of Physics, SB of RAS)
  • Ovchinnikov S.G. (Siberian State Aerospace University)
  • Knyazev Y.V. (Siberian Federal University)
  • Arauzo A. (Servicio de Medidas Fisicas, Universidad de Zaragoza)

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