Sensors (Jul 2012)

Magnetic Properties of Liquid-Phase Sintered CoFe<sub>2</sub>O<sub>4</sub> for Application in Magnetoelastic and Magnetoelectric Transducers

  • Leonardo Violim Lemos,
  • Stéphanie Alá Cunha,
  • Vera Lúcia Othéro de Brito,
  • Cristina Bormio Nunes

DOI
https://doi.org/10.3390/s120810086
Journal volume & issue
Vol. 12, no. 8
pp. 10086 – 10096

Abstract

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Cobalt ferrite is a ferrimagnetic magnetostrictive ceramic that has potential application in magnetoelastic and magnetoelectric transducers. In this work, CoFe<sub>2</sub>O<sub>4</sub> was obtained using a conventional ceramic method and Bi<sub>2</sub>O<sub>3</sub> was used as additive in order to obtain liquid-phase sintered samples. Bi<sub>2</sub>O<sub>3</sub> was added to the ferrite in amounts ranging from 0.25 mol% to 0.45 mol% and samples were sintered at 900 °C and 950 °C. It was observed the presence of Bi-containing particles in the microstructure of the sintered samples and the magnetostriction results indicated microstructural anisotropy. It was verified that it is possible to get dense cobalt ferrites, liquid-phase sintered, with relative densities higher than 90% and with magnetostriction values very close to samples sintered without additives.

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