Doped Cobalt Ferrites for Stress Sensor Applications

Abstract

The development of new magnetoelastic materials, suitable for use in magnetic stress sensors, has a high scientific and technological interest due to growing number of possible applications in automotive industry. In this study, a series of silicon-doped cobalt ferrite samples with compositions of CoSi,Fe2,X04 were prepared by substituting silicon for iron. The samples were made using standard powder ceramic technique. The spinel structure and the presence of residual phases were checked by XRD analysis. To determine the influence of the substitution on the strength of the magnetic exchange interactions, Curie temperature (Tc) measurements were made. A dramatic decrease of Tc with the substitution of Si for Fe was observed. By adjusting the silicon content and the sintering process the material properties could be optimized for industrial application.

Suitability of cation substituted cobalt ferrite materials for magnetoelastic sensor applications

“…The structural and magnetic properties of the samples have been reported previously [11]. Figure 2 shows how the Curie temperature varies with concentration of substituted cations in different chemically substituted variants of cobalt ferrite [13][14][15][16][17], including the Ti-substituted samples reported in this study. All the cation substitutions resulted in a decrease of Curie temperature which is indicative of the weakening of the super-exchange coupling between the moments of the cations in the A-sites and B-sites due to the introduction of nonmagnetic cations into either of the cation sites.…”

“…All the cation substitutions resulted in a decrease of Curie temperature which is indicative of the weakening of the super-exchange coupling between the moments of the cations in the A-sites and B-sites due to the introduction of nonmagnetic cations into either of the cation sites. The Curie temperatures reported at x = 0.0 in [13][14][15][16][17] are not indicated in figure 2 since the values differ in those different studies. This is an expected consequence of different processing conditions and different methods of Curie temperature determination.…”

“…Nevertheless, the focus in this work is on the resultant effect of the substituted cation on the properties. In another study, Si 4+ was substituted for Fe 3+ without Co 2+ co-substitution which also resulted in decreased magnetostriction amplitude [17]. This therefore suggests that the increase in magnetostriction amplitude in…”

Ni-Zn Ferrite-graphene Nanohybrids: Synthesis and Characterization of Magnetic and Microwave Absorbing Properties

“…The values of magnetic measurements were determined from hysteresis loops and were summarized in Table 1. NZF nanoparticles recorded the highest M S of 42.50 emu/g, which is higher than that produced in [5,13] but lower than that produced in [9]. A thin hysteresis was observed, showing the ferromagnetism of the nanoparticles at room temperature.…”