Influence of silicon and cobalt substitutions on magnetostriction coefficient of cobalt ferrite

Rao, G. S. N.; Caltun, Ovidiu Florin; Rao, K. H.; Rao, B. Bhaskara; Wamocha, Humphrey Lusenaka; Hamdeh, Hussein H.

doi:10.1007/978-3-540-78697-9_80

Cited by 5 publications

(4 citation statements)

References 8 publications

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“…However, the observed increase in dc resistivity suggests the formation of Ti 4+ -Fe 2+ locking pairs [13,14]. For lower concentration of titanium (x ≤ 0.1), the observed low value of dc resistivity might be due to the presence of generated Fe 2+ ions at elevated sintering temperature in the sample in spite of the presence of Ti 4+ -Fe 2+ pairs.…”

Section: Resistivitymentioning

confidence: 99%

Cation distribution of titanium substituted cobalt ferrites

Rao

Kumar

Varma

et al. 2009

Journal of Alloys and Compounds

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Section: Resistivitymentioning

confidence: 99%

Cation distribution of titanium substituted cobalt ferrites

Rao

Kumar

Varma

et al. 2009

Journal of Alloys and Compounds

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“…However, the highest maximum strain obtained for the sample is very low as 150 ppm. Enhancement in the strain sensitivity is reported after substitution of metal ions in the cobalt ferrite lattice, but at the cost of the magnetostriction strain [13][14][15][16][17]. It has been shown that the strain sensitivity can be enhanced, without affecting the magnetostriction coefficient, for sintered Mn-substituted cobalt ferrite made from nanosized powders [18].…”

Section: Introductionmentioning

confidence: 99%

Magnetic and magnetostrictive properties of aluminium substituted cobalt ferrite synthesized by citrate-gel method

Anantharamaiah

Joy

2015

J Mater Sci

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Structural, magnetic and magnetostrictive properties of sintered aluminium-substituted cobalt ferrite, CoAl x Fe 2-x O 4 (x = 0.0, 0.1, 0.20, 0.30), derived from nanosized powders synthesized by a citrate-gel method, have been investigated. The sample with x = 0.1 is found to exhibit higher maximum magnetostriction strain at relatively lower magnetic fields (230 ppm at 286 kA/m) than that obtained for the unsubstituted cobalt ferrite (217 ppm, at 446 kA/m). All the Al-substituted compositions show larger strain sensitivity (dk/dH) at low magnetic fields compared to that for the unsubstituted cobalt ferrite. The variation of the magnetostriction coefficient as well as the strain sensitivity with Al content is likely to be due to the changes in the cation distribution in the tetrahedral and octahedral sites of the spinel lattice along with the associated changes in the magnetocrystalline anisotropy. The magnetostriction coefficient of x = 0.1 could be further enhanced to 306 ppm (at 220 kA/m) after a magnetic field annealing at 300°C. A very high strain sensitivity of 4.5 9 10 -9 m/A is obtained for the magnetically annealed sample, larger than that reported for any substituted cobalt ferrite samples. The combination of high magnetostriction coefficient and strain sensitivity is suitable for device applications.

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“…Here, it is important to note that from the thermal variation of dc resistivity measurements, no such change in the vicinity to corresponding T N value was observed. 20,21 One can draw two significant findings: (i) the activation energy values increase with an increase in temperature (E p > E f ) at a constant frequency. This can be attributed to more energy required to overcome the thermal fluctuations by the charge carriers i.e., electrons, at the high-temperature region.…”

Section: Resultsmentioning

confidence: 99%

Master curve generation and modeling of ac conductivity for Mn0.7+xZn0.3Si_xFe2–2xO₄ spinel ferrite system

Vasoya

Jha

Saija³

et al. 2017

J. Adv. Dielect.

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The compositional dependence of ac conductivity ( ac ), real (′) and imaginary (′′) parts of complex electric conductivity (*) was investigated as a function of temperature (T) and frequency (f Þ for Mn 0:7þx Zn 0:3 Si x Fe 2À2x O 4 , x ¼ 0:0, 0.1, 0.2 and 0.3 spinel ferrite system. The compositional dependence of lattice constant values suggested that the most of the substituted Si 4þ -ions reside at grain boundaries and only a few Si-ions are inside grains. The variation of ac ðx, f , TÞ is explained on the basis of segregation and diffusion of Si 4þ ions at grain boundaries and grains, respectively, and the electrode effect. Thermal variation of ac conductivity at fixed frequency suggested two different mechanisms which could be responsible for conduction in the system. It is found that * is not the preferred presentation for dielectric data and the scaling process of real part of conductivity by normalized frequency and the scaled frequency were found unsuccessful. The fitting results of ac conductivity data with path percolation approximation were found suitable in low-frequency regime while in high-frequency regime, effective medium approximation (EMA) was found successful.

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Influence of silicon and cobalt substitutions on magnetostriction coefficient of cobalt ferrite

Cited by 5 publications

References 8 publications

Cation distribution of titanium substituted cobalt ferrites

Cation distribution of titanium substituted cobalt ferrites

Magnetic and magnetostrictive properties of aluminium substituted cobalt ferrite synthesized by citrate-gel method

Master curve generation and modeling of ac conductivity for Mn0.7+xZn0.3Si_xFe2–2xO₄ spinel ferrite system

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Influence of silicon and cobalt substitutions on magnetostriction coefficient of cobalt ferrite

Cited by 5 publications

References 8 publications

Cation distribution of titanium substituted cobalt ferrites

Cation distribution of titanium substituted cobalt ferrites

Magnetic and magnetostrictive properties of aluminium substituted cobalt ferrite synthesized by citrate-gel method

Master curve generation and modeling of ac conductivity for Mn0.7+xZn0.3SixFe2–2xO4 spinel ferrite system

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Master curve generation and modeling of ac conductivity for Mn0.7+xZn0.3Si_xFe2–2xO₄ spinel ferrite system