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Title: Exchange spring behaviour in SrFe{sub 12}O{sub 19}-CoFe{sub 2}O{sub 4} nanocomposites

Nanocomposites of hard (SrFe{sub 12}O{sub 19}) and soft ferrite (CoFe{sub 2}O{sub 4}) are prepared by mixing individual ferrite components at appropriate weight ratio and subsequent heat treatment. The magnetization of the composites showed hysteresis loop that is characteristic of the exchange spring system. The variation of J{sub r}/J{sub r}(∞) vs. J{sub d}/ J{sub r}(∞) for these nanocomposites are investigated to understand the presence of both the interacting field and the disorder in the system. This is further corroborated with the First Order Reversal Curve analysis (FORC) on the nanocomposites of 1:4 (Cobalt Ferrite: Strontium Ferrite) and 1:16 (Cobalt Ferrite: Strontium Ferrite). The FORC distribution reveals that the pinning mechanism is stronger in the nanocomposite of 1:4 compared to 1:16. However, the nanocomposite of 1:16 exhibit superior exchange coupling strength in contrast to 1:4. The asymmetric nature of the FORC distribution at H{sub c} = 0 Oe for both the nanocomposites validates the intercoupling between the reversible and irreversible magnetization.
Authors:
;  [1]
  1. Department of Physics, Indian Institute of Science, Bangalore 560012 (India)
Publication Date:
OSTI Identifier:
22493949
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 7; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ASYMMETRY; COBALT OXIDES; COMPARATIVE EVALUATIONS; COUPLING; FERRITES; HEAT TREATMENTS; HYSTERESIS; MAGNETIZATION; NANOCOMPOSITES; STRONTIUM COMPOUNDS; VARIATIONS