Effect of High-Anisotropic Co Substitution for Ni on the Structural, Magnetic, and Magnetostrictive Properties of NiFeO: Implications for Sensor Applications.

This work reports on the effect of substituting a low-anisotropic and low-magnetic cation (Ni, 2μ) by a high-anisotropic and high-magnetic cation (Co, 3μ) on the crystal structure, phase, microstructure, magnetic properties, and magnetostrictive properties of NiFeO (NFO). Co-substituted NFO (NiCoFeO, NCFO, 0 ≤ ≤ 1) nanomaterials were synthesized using glycine-nitrate autocombustion followed by postsynthesis annealing at 1200 °C. The X-ray diffraction measurements coupled with Rietveld refinement analyses indicate the significant effect of Co-substitution for Ni, where the lattice constant () exhibits a functional dependence on composition ().

Structural, Magnetic, and Magnetostriction Properties of Flexible, Nanocrystalline CoFeO Films Made by Chemical Processing.

We report on the simple, single-step, and cost-effective fabrication, characterization, and performance evaluation of cobalt ferrite (CoFeO; CFO) nanocrystalline (NC) thin films on a flexible mica substrate. The chemical solution-based drop-casting method employed to fabricate crystalline CFO films and their characterization was performed by studying the phase formation, surface morphology, and magnetic parameters, while sensor applicability was evaluated using combined magnetic and magnetostrictive properties. X-ray diffraction (XRD) indicates the single-phase and nanocrystalline nature of CFO films, where the crystallite size is ∼60 nm.

Aluminum Doping and Nanostructuring Enabled Designing of Magnetically Recoverable Hexaferrite Catalysts.

We demonstrate an approach based on substituting a magnetic cation with a carefully chosen isovalent non-magnetic cation to derive catalytic activity from otherwise catalytically inactive magnetic materials. Using the model system considered, the results illustratively present that the catalytically inactive but highly magnetic strontium hexaferrite (SrFeO; SFO) system can be transformed into a catalytically active system by simply replacing some of the magnetic cation Fe by a non-magnetic cation Al in the octahedral coordination environment in the SFO nanocrystals. The intrinsic SFO and Al-doped SrFeO (SrFeAlO; Al-SFO) nanomaterials were synthesized using a simple, eco-friendly tartrate-gel technique, followed by thermal annealing at 850 °C for 2 h.

Role of Mg and In substitution on magnetic, magnetostrictive and dielectric properties of NiFeO ceramics derived from nanopowders.

The effect of Mg2+ and In3+ substitution on the structural, magnetic, magnetostrictive and dielectric properties of NiFe2O4 samples derived through sintering of nanocrystalline ceramic powders is investigated. Namely, NiFe2O4, NiMg0.2Fe1.