Exchange-spring mechanism of soft and hard ferrite nanocomposites

Hoque, Manjura S and Srivastava, C and Kumar, V and Venkatesh, N and Das, HN and Saha, DK and Chattopadhyay, K (2013) Exchange-spring mechanism of soft and hard ferrite nanocomposites. In: Materials Research Bulletin, 48 (8). pp. 2871-2877.

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Abstract

The paper reports exchange-spring soft and hard ferrite nanocomposites synthesized by chemical co-precipitation with or without the application of ultrasonic vibration. The composites contained BaFe12O19 as the hard phase and CoFe2O4/MgFe2O4 as the soft phase. X-ray diffraction patterns of the samples in the optimum calcined condition indicated the presence of soft ferrites as face-centred cubic (fcc) and hard ferrites as hexagonal close packed (hcp) structure respectively. Temperature dependence of magnetization in the range of 20-700 degrees C demonstrated distinct presence of soft and hard ferrites as magnetic phases which are characterized by wide difference in magnetic anisotropy and coercivity. Exchange-spring mechanism led these nanocomposite systems to exchange-coupled, which ultimately produced convex hysteresis loops characteristic of a single-phase permanent magnet. Fairly high value of coercivity and maximum energy product were observed for the samples in the optimum calcined conditions with a maximum applied field of 1600 kA/m (2 T).

Item Type:	Journal Article
Publication:	Materials Research Bulletin
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Nanostructures; Magnetic Materials; Chemical Synthesis; X-Ray Diffraction; Magnetic Properties
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	02 Sep 2013 06:22
Last Modified:	02 Sep 2013 06:22
URI:	http://eprints.iisc.ac.in/id/eprint/46948

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