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Magnetic properties of liquid-phase sintered CoFe₂O₄ for application in magnetoelastic and magnetoelectric transducers.

de Brito VL, Cunha SA, Lemos LV, Nunes CB - Sensors (Basel) (2012)

Bottom Line: Bi(2)O(3) 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.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Estudos Avançados, Rodovia dos Tamoios, km 5,5, Putim, São José dos Campos, SP 12228-001, Brazil. vlobrito@ieav.cta.br

ABSTRACT
Cobalt ferrite is a ferrimagnetic magnetostrictive ceramic that has potential application in magnetoelastic and magnetoelectric transducers. In this work, CoFe(2)O(4) was obtained using a conventional ceramic method and Bi(2)O(3) was used as additive in order to obtain liquid-phase sintered samples. Bi(2)O(3) 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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Magnetoelastic sensitivities (∂λ/∂(μ0H)) vs. applied field. (a) Magnetoelastic sensitivity parallel to the applied field. (b) Magnetoelastic sensitivity perpendicular to the applied field.
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f5-sensors-12-10086: Magnetoelastic sensitivities (∂λ/∂(μ0H)) vs. applied field. (a) Magnetoelastic sensitivity parallel to the applied field. (b) Magnetoelastic sensitivity perpendicular to the applied field.

Mentions: The anisotropy induced by the presence of the second phases increased considerably the linear magnetostriction and this is a very interesting characteristic for the development of force sensors, for example. Figure 5 shows the curves of the magnetoelastic sensitivities vs. applied field and Table 3 shows the maximum magnetoelastic sensitivity and the internal field value at which it occurs in the longitudinal and transversal modes.


Magnetic properties of liquid-phase sintered CoFe₂O₄ for application in magnetoelastic and magnetoelectric transducers.

de Brito VL, Cunha SA, Lemos LV, Nunes CB - Sensors (Basel) (2012)

Magnetoelastic sensitivities (∂λ/∂(μ0H)) vs. applied field. (a) Magnetoelastic sensitivity parallel to the applied field. (b) Magnetoelastic sensitivity perpendicular to the applied field.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472817&req=5

f5-sensors-12-10086: Magnetoelastic sensitivities (∂λ/∂(μ0H)) vs. applied field. (a) Magnetoelastic sensitivity parallel to the applied field. (b) Magnetoelastic sensitivity perpendicular to the applied field.
Mentions: The anisotropy induced by the presence of the second phases increased considerably the linear magnetostriction and this is a very interesting characteristic for the development of force sensors, for example. Figure 5 shows the curves of the magnetoelastic sensitivities vs. applied field and Table 3 shows the maximum magnetoelastic sensitivity and the internal field value at which it occurs in the longitudinal and transversal modes.

Bottom Line: Bi(2)O(3) 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.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Estudos Avançados, Rodovia dos Tamoios, km 5,5, Putim, São José dos Campos, SP 12228-001, Brazil. vlobrito@ieav.cta.br

ABSTRACT
Cobalt ferrite is a ferrimagnetic magnetostrictive ceramic that has potential application in magnetoelastic and magnetoelectric transducers. In this work, CoFe(2)O(4) was obtained using a conventional ceramic method and Bi(2)O(3) was used as additive in order to obtain liquid-phase sintered samples. Bi(2)O(3) 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.

Show MeSH