12 results about "Spinel ferrite" patented technology

The application discloses a kind of microspheroidal high-entropy spinel type ferrite wave-absorbing materials and preparation method thereof, belong to electromagnetic wave absorbing material technical field, the preparation method includes with the designed molar ratio six metal nitrate is weighed and dissolved in deionized water, then add ammonium fluoride, urea, after stirring, the obtained solution is hydrothermal reaction at a certain temperature for a certain time to obtain precursor, the precursor is calcined to obtain microspheroidal high-entropy spinel type ferrite.The obtained wave-absorbing material is single-phase spinel structure, micron-sized spherical morphology, its chemical formula is MFe2O4;Wherein M=Co, Ni, Cu, Zn, Cr.The microspheroidal high-entropy spinel type ferrite wave-absorbing material and preparation method thereof are used, and the performance of pure ferrite wave-absorbing material can be effectively improved, with the characteristics of simple preparation, strong absorption performance, absorption frequency bandwidth.

The invention relates to the technical field of ferrite single-crystal materials, in particular to a treatment method for improving the ferromagnetic resonance line width of spinel NiZn ferrite single-crystal pellets, which comprises the following steps: annealing the spinel NiZn ferrite single-crystal pellets under the conditions of high oxygen pressure and high temperature, slowly cooling to room temperature, and releasing the pressure after the annealing is finished, thereby obtaining the spinel NiZn ferrite single-crystal pellets. According to the method, the NiZn ferrite single crystal pellets are subjected to annealing treatment by adopting a high-oxygen-pressure high-temperature annealing treatment process, the pellet processing stress can be released under the condition of inhibiting Zn element volatilization, the ferromagnetic resonance line width of the NiZn ferrite single crystal pellets can be effectively reduced, and subsequent pellet surface polishing treatment is also facilitated.

A system for the synthesis of magnetoelectronically tunable spinel ferrite nanoparticles, comprising: a) a precursor preparation unit for the preparation of a homogeneous nitrate precursor solution, wherein the precursor preparation unit facilitates the dissolution of stoichiometric amounts of magnesium nitrate hexahydrate, nickel nitrate hexahydrate, iron(III) nitrate nonahydrate and chromium(III) nitrate nonahydrate in deionized water; b) a fuel mixing unit configured to introduce a binary mixture of urea and glucose into the dissolved homogeneous nitrate solution in a fuel-oxidant ratio that achieves fuel equivalence; c) a gel formation unit configured to maintain the temperature at 70-80 °C under continuous stirring to convert the fuel mixture into a viscous gel; d) a combustion unit comprising a preheated muffle furnace maintained at 450 ± 10 °C and enabling the initiation of a self-propagating combustion reaction; and e) a calcination plant configured for the thermal treatment of crushed precursor ash at 600 °C for 2 hours and subsequently at 750 °C for 2 hours to produce phase-pure cubic spinel Mg 1-x Ni x To produce FeCrO4 nanoparticles.

The present application relates to a kind of cobalt-based spinel ferrite nanoparticles with zero-field magnetic quantum tunneling properties and its application, the inside of the nanoparticle has the topological structure of broken spatial symmetry;The topological structure includes the first topological domain and the second topological domain distributed staggeredly in space, so that the cobalt-based spinel ferrite nanoparticle produces intrinsic transverse tunneling energy level splitting under zero applied magnetic field.The sharp stepwise magnetization jump of the cobalt-based spinel ferrite nanoparticle of the present application at zero field can realize the high sensitivity nonlinear response to weak magnetic field, and can be applied to the preparation and development of low-temperature quantum sensing probe or multi-level nonvolatile logic memory.

The invention discloses a screening method of a quaternary spinel ferrite type photocatalytic material. The method comprises the following steps: firstly, constructing a series of quaternary spinel ferrite models, then carrying out sufficient structural relaxation by utilizing a first principle, evaluating thermodynamic and dynamic stability of the models through formation energy and calculation of a phonon spectrum, and further calculating an energy band structure, a band edge position, electron effective mass and hole effective mass of the models; the influence of different tetrahedron center atoms on the electronic structure of the spinel type material is analyzed and compared, and the quaternary spinel type material suitable for being used in the photocatalysis field is screened out according to the requirement of an ideal photocatalysis material on the electronic structure of the material.

The invention discloses a method for screening a spinel type ferrite AFe2O4 / two-dimensional material heterojunction photocatalytic material, which comprises the following steps of: constructing a series of spinel type ferrite AFe2O4 / two-dimensional material heterojunction structure models, then carrying out sufficient structure optimization to obtain a ground state heterojunction structure, and calculating the adsorption energy of a two-dimensional material and a matrix, so as to obtain the spinel type ferrite AFe2O4 / two-dimensional material heterojunction photocatalytic material. The method comprises the following steps of: performing de novo molecular dynamics simulation to evaluate the stability, further calculating the differential charge density, the energy band structure and the band edge position, screening, analyzing and comparing the influence of different two-dimensional materials on the electronic structure of the spinel type material, and screening out a spinel type ferrite / two-dimensional material heterojunction structure model suitable for the photocatalysis field.

The invention discloses a spinel ferrite photocatalytic material screening method based on synergic regulation and control of reversal degrees and A-site cations. The method comprises the following steps: firstly, constructing AFe2O4 type spinel ferrite structure models of different A-site cations and [AxFe1-x] [Fe2-yAy] O4 type spinel ferrite structure models of different reversal degrees; then, the formation energy and phonon spectrum of each model are calculated by adopting a first principle, and unstable models are removed; the electron energy band structure, the carrier effective mass and the light absorption coefficient of the reserved thermodynamically and dynamically stable model are further calculated with high precision, and the model meeting the requirements of the ideal photocatalytic material electron structure and the light absorption coefficient is reserved; and then calculating the carrier mobility based on a deformation potential theory, calculating the service life of the optical excitation carrier by using a non-adiabatic molecular dynamics method, and preferably selecting a model with high mobility and long service life of the carrier as a potential photocatalytic material.

A nanocomposite electrode and supercapacitor thereof are disclosed. The nanocomposite electrode includes a substrate, at least one binding compound, at least one carbonaceous compound, and vanadium doped spinel ferrite nanoparticles (V-SFNPs). The V-SFNPs have a formula of CoxNi1-xVyFe2-yOz, wherein x=0.1-0.9, y=0.01-0.10, and z=3-5. The substrate is at least partially coated on a first side with a mixture comprising the V-SFNPs, the at least one binding compound, and the at least one carbonaceous compound. Two of the nanocomposite electrodes are combined to form the supercapacitor.

A magnetoelectric multiferroic nanocomposite. The nanocomposite comprises a ferroelectric perovskite oxide and a rare-earth substituted mixed ternary transition metal ferrite of the formula A1-xBxRyFe2-yO4. The nanocomposite has a high dielectric constant, low dielectric loss, both stable over a wide frequency range. These properties may make the nanocomposite desirable for applications in microelectronic devices, sensors and antennas.

Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.

A method of fertilizing a plant including applying a composition to a root of the plant. The composition includes a spinel ferrite with a formula of MnxZnyFe2O4, where x+y=1. Particles of the spinel ferrite are spherical and have an average diameter of 10-20 nm. The plant has at least a 40% increase in leaf size compared to a plant under the same conditions but without applying the composition.

The invention relates to the technical field of ferrite single crystal materials, in particular to a method for growing a spinel type ferrite single crystal material with low ferromagnetic resonance line width, which comprises the following steps: grinding and uniformly mixing raw materials and a cosolvent, then carrying out slow cooling growth under a sealing condition, and after the growth is finished, removing the cosolvent to obtain the spinel type ferrite single crystal material with low ferromagnetic resonance line width, the cosolvent is prepared from PbO2, Bi2O3 and B2O3.