Processing and characterization of a Ni-Co ferrite for sensor applications

Author(s)

V. L. O. Brito ; S. A. Cunha ^[2] ; F. F. Araújo ^[3] ; J. P. B. Machado ^[4] ; M. R. Silva ^[5] ; C. B. Nunes ^[6]

• Document type: Journal article
• Source: Cerâmica; v. 61, n. 359, p. 341-349, 2015-09-00.

Abstract

AbstractNi-Co ferrites are magnetostrictive ceramics that have potential application in magnetostrictive/ magnetoelastic sensors, as well as in magnetoelectric composites. Ni-rich Ni-Co spinel ferrite samples were processed by the ceramic method and bulk samples were sintered at 1350 ºC in the solid state and at 950 ºC with Bi2O3 liquid phase. The sintered samples were characterized by light microscopy, scanning electron microscopy, Raman spectroscopy, vibrating sample magnetometry and capacitance dilatometry. With Bi2O3 additions as small as 0.6 mol% it was possible to sinter the Ni-Co ferrite at 950 ºC, obtaining high-density samples; however, such liquid-phase sintered samples presented iron oxide particles. The studied samples presented magnetoelastic sensitivities very close to CoFe2O4, with significantly lower magnetic hysteresis. The results thus indicate that the magnetic properties of the samples analyzed are suitable for applications in magnetomechanical sensors. (AU)

• FAPESP's process: 12/01448-2 - Cobalt ferrite development to sensors enclosering application to RF and microwave
• Grantee: Antonio Carlos da Cunha Migliano
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/21258-0 - Construction of a force sensor using Fe-Ga and Fe-Al doped with boron
• Grantee: Cristina Bormio Nunes
• Support Opportunities: Regular Research Grants
• FAPESP's process: 09/09524-7 - Characterization of the magnetostriction of cobalt ferrites
• Grantee: Vera Lúcia Othéro de Brito
• Support Opportunities: Regular Research Grants