Non-equilibrium cation influence on the Néel temperature in ZnFe2O4

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

Research output: Contribution to journalArticle

8 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

Fingerprint

Cations
Magnetization
Ferrites
Positive ions
Scaling laws
Saturation magnetization
Curie temperature
Temperature
Hot Temperature

Keywords

  • Ferrites
  • Néel temperature
  • Zinc ferrite
  • ZnFeO

ASJC Scopus subject areas

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

Cite this

Non-equilibrium cation influence on the Néel temperature in ZnFe2O4 . / Stewart, S. J.; Al-Omari, I. A.; Sives, F. R.; Widatallah, H. M.

In: Journal of Alloys and Compounds, Vol. 495, No. 2, 16.04.2010, p. 506-508.

Research output: Contribution to journalArticle

@article{f3652c24d90f46f7a4fb021096874f61,
title = "Non-equilibrium cation influence on the N{\'e}el temperature in ZnFe2O4",
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 N{\'e}el 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.",
keywords = "Ferrites, N{\'e}el temperature, Zinc ferrite, ZnFeO",
author = "Stewart, {S. J.} and Al-Omari, {I. A.} and Sives, {F. R.} and Widatallah, {H. M.}",
year = "2010",
month = "4",
day = "16",
doi = "10.1016/j.jallcom.2009.10.258",
language = "English",
volume = "495",
pages = "506--508",
journal = "Journal of Alloys and Compounds",
issn = "0925-8388",
publisher = "Elsevier BV",
number = "2",

}

TY - JOUR

T1 - Non-equilibrium cation influence on the Néel temperature in ZnFe2O4

AU - Stewart, S. J.

AU - Al-Omari, I. A.

AU - Sives, F. R.

AU - Widatallah, H. M.

PY - 2010/4/16

Y1 - 2010/4/16

N2 - 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.

AB - 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.

KW - Ferrites

KW - Néel temperature

KW - Zinc ferrite

KW - ZnFeO

UR - http://www.scopus.com/inward/record.url?scp=77951091591&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77951091591&partnerID=8YFLogxK

U2 - 10.1016/j.jallcom.2009.10.258

DO - 10.1016/j.jallcom.2009.10.258

M3 - Article

VL - 495

SP - 506

EP - 508

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

IS - 2

ER -