Photomagnetism and structure in cobalt ferrite nanoparticles

Effects of alignment, pH, surfactant, and solvent on heat transfer nanofluids containing Fe2O3 and CuO nanoparticles J. Appl. Phys. 111, 064308 (2012) Size effect on the structural, magnetic, and magnetotransport properties of electron doped manganite La0.15Ca0. Curie temperature for this series is found to be in the range of 618-766 K. Room temperature resistivity increases gradually from 7.5 Â 10 8 X cm (x ¼ 0.0) to 3.47 Â 10 9 X cm (x ¼ 0.5). Additionally, dielectric measurements are carried out at room temperature in a frequency range of 100 Hz to 3 MHz. With improvement in the values of the above-mentioned properties, the synthesized materials could be suitable for potential application in some magnetic and microwave devices.

Section: Introductionmentioning

confidence: 99%

Physical, electrical and magnetic properties of nano-sized Co-Cr substituted magnesium ferrites

Iqbal

Ahmad

Meydan

et al. 2012

“…Due to exceptional magnetoelastic, magnetotransport, magnetooptical, photomagnetic, electronic, and magnetic properties, cobalt ferrite ͑CFO͒ has been proposed for applications in noncontact force and torque sensors, 1 as spin filters for magnetic tunnel junctions, 2 for hybrid data storage, 3 for magnetooptical media, 4 and as anode materials for advanced Li-ion batteries. 5 Depending on the requirements of application, magnetic and magnetoelastic properties of CFO can be fine-tuned by appropriate cation substitution 1,[6][7][8] and magnetic annealing.…”

Section: Introductionmentioning

confidence: 99%

Growth of crystalline cobalt ferrite thin films at lower temperatures using pulsed-laser deposition technique

Raghunathan

Nlebedim

Jiles

et al. 2010

Threading dislocation-governed degradation in crystal quality of heteroepitaxial materials: The case of InAlN nearly lattice-matched to GaN J. Appl. Phys. 111, 053535 (2012) Ferroelectric domain structures of 0.4-μm-thick Pb(Zr,Ti)O3 films prepared by polyvinylpyrrolidone-assisted SolGel method J. Appl. Phys. 111, 054109 (2012) Columnar grain growth of FePt (L10) Cobalt ferrite thin films were grown on SiO 2 / Si͑100͒ substrates using pulsed-laser deposition technique at substrate temperatures ranging from 250 to 600°C. Thermal expansion mismatch between the film and substrate appears to have a substantial effect on the magnetic properties of the cobalt ferrite films, due to the large magnetoelastic coupling of cobalt ferrite. It was shown in this study, that polycrystalline films with ͑111͒-preferred orientation could be prepared at substrate temperatures as low as 250°C. The growth of crystalline cobalt ferrite films at such low temperatures indicates the potential to use cobalt ferrite for microelectromechanical systems devices and sensor applications including integration with a wider range of multilayer device structures.

“…For example, photomagnetism in nanoparticles of cobalt ferrite have been related to this type of cation distribution. 1 Its higher magnetocrystalline anisotropy and stronger magnetomechanical effects compared to other spinel ferrites are due to the orbital angular momentum of Co 2þ not being completely quenched by the crystalline field. Consequently, Co 2þ on the octahedral sites of the crystal lattice contributes an orbital moment, comparable to the spin moment, resulting in strong spin-orbit coupling which is responsible for the characteristic properties of cobalt ferrite.…”

mentioning

confidence: 99%

Temperature dependence of magnetic properties of heat treated cobalt ferrite

Nlebedim¹,

Melikhov²,

Jiles³

2014

This study demonstrates the effectiveness of heat treatment in optimizing the magneticproperties of cobalt ferrite, compared to other methods such as cation substitution. It also shows how the magnetic properties of the heat treated cobalt ferrite vary under differenttemperature conditions. Saturation magnetization increased more due to heat treatment than due to Zn-substitution; a cation substitution that is known to result in high saturationmagnetization in ferrites. A remarkable observation is that the increase in the saturationmagnetization due to heat treatment was not at the expense of Curie temperature as was often reported for cation substituted materials. The observed variations in the magnetic propertieswere explained on the basis of cation redistribution arising as a result of the heat treatment. KeywordsAmes Laboratory, Heat treatments, Ferrites, Cobalt, Saturation moments, Thermal properties Disciplines Electromagnetics and Photonics CommentsThe following article appeared in Journal of Applied Physics 115 (2014) This study demonstrates the effectiveness of heat treatment in optimizing the magnetic properties of cobalt ferrite, compared to other methods such as cation substitution. It also shows how the magnetic properties of the heat treated cobalt ferrite vary under different temperature conditions. Saturation magnetization increased more due to heat treatment than due to Zn-substitution; a cation substitution that is known to result in high saturation magnetization in ferrites. A remarkable observation is that the increase in the saturation magnetization due to heat treatment was not at the expense of Curie temperature as was often reported for cation substituted materials. The observed variations in the magnetic properties were explained on the basis of cation redistribution arising as a result of the heat treatment. V C 2014 AIP Publishing LLC. [http://dx