Non-equilibrium cation influence on the Néel temperature in ZnFe2O4

S. J. Stewart, I. A. Al-Omari, F. R. Sives, H. M. Widatallah

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9 Citations (Scopus)

Abstract

We present results on the thermal dependence of the magnetization above ambient conditions of ZnFe2O4 nanoferrites having different degrees of inversion (c ∼ 0.05-0.40) and grain sizes (D ∼ 6-50 nm). The disordered ferrites present a net magnetization in the 400-510 K range that mainly depends on the degree of inversion. The reciprocal magnetization deviate from different temperature values of the linear behavior showed at high temperatures. Our results show that, contrary to similar nanoferrite systems, a simple scaling law cannot be applied to explain the Néel temperature TN dependency with the grain size. These results can be interpreted in terms of the lack of correlation between size and inversion that occurs in ZnFe2O4 and the strong TN dependence on the superexchange JAB interaction strength. A model assuming a random distribution of superexchange interactions can reproduce the Curie-Weiss temperature and the saturation magnetization values of the disordered ferrites.

Original languageEnglish
Pages (from-to)506-508
Number of pages3
JournalJournal of Alloys and Compounds
Volume495
Issue number2
DOIs
Publication statusPublished - Apr 16 2010

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Keywords

  • Ferrites
  • Néel temperature
  • Zinc ferrite
  • ZnFeO

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Chemistry
  • Metals and Alloys

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