Radiofrequency and other electronic devices can be formed from textured hexaferrite materials, such as Z-phase barium cobalt ferrite Ba.sub.3Co.sub.2Fe.sub.24O.sub.41 (Co.sub.2Z) having enhanced resonant frequency. The textured hexaferrite material can be formed by sintering fine grain hexaferrite powder at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The textured hexaferrite material can be used in radiofrequency devices such as circulators or telecommunications systems.

A powder for dust cores includes an aggregate of soft magnetic particles, each of which includes a soft magnetic metal particle, and a ferrite film that covers a surface of the soft magnetic metal particle and includes ferrite crystal grains having a spinel structure. A diffraction peak derived from the ferrite crystal grains exists in a powder X-ray diffraction pattern. By a method for producing a powder for dust cores, a raw material powder that includes an aggregate of soft magnetic metal particles is prepared. Furthermore, many ferrite fine particles are formed on a surface of each of the soft magnetic metal particles of the raw material powder. Additionally, the ferrite fine particles are coarsely crystallized through heat treatment to form a ferrite film, which includes ferrite crystal grains having a spinel structure, on the surface of the each of the soft magnetic metal particles.

Some variations provide a method of making water-dispersed hexaferrite nanoparticles, comprising: providing a first salt containing iron, a second salt containing barium and/or strontium, and a third salt containing an anion or cation that is capable of forming a ligand with the hexaferrite nanoparticles; combining the first salt, second salt, third salt, and water to form a reaction mixture; subjecting the reaction mixture to effective reaction conditions to produce hexaferrite nanoparticles with the anion or cation in the third salt forming a ligand on the surface, so that the hexaferrite nanoparticles are dissolved and/or suspended in the reaction mixture; and obtaining water-dispersed hexaferrite nanoparticles with an average zeta potential of at least 20 mV. The water-dispersed hexaferrite nanoparticles have a hexaferrite content of at least 85 wt %. The method may further include assembling water-dispersed hexaferrite nanoparticles into a magnetic component, such as a self-biased hexaferrite film on a semiconductor substrate.

A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet comprises La and Co, a content of B is 0.005 to 0.9% by mass in terms of B.sub.2O.sub.3, a content of Zn is 0.01 to 1.2% by mass in terms of ZnO, and the ferrite sintered magnet satisfies [La]/[Zn]0.79 and [Co]/[Zn]0.67 when an atomic concentration of La is represented by [La], an atomic concentration of Co is represented by [Co], and an atomic concentration of Zn is represented by [Zn].

An object of the present invention is to provide a ferrite carrier core material for an electrophotographic developer having desired resistance properties and charging properties with small environmental variation of resistivity and charge amount while maintaining the advantages of ferrite carriers, a ferrite carrier for an electrophotographic developer, an electrophotographic developer using the ferrite carrier, and a method for manufacturing the ferrite carrier core material for an electrophotographic developer. In order to solve the problem, a ferrite carrier core material comprising ferrite particles containing 15 mass % or more and 25 mass % or less of Mn, 0.5 mass % or more and 5.0 mass % or less of Mg, 0.05 mass % or more and 4.0 mass % of Sr, and 45 mass % or more and 55 mass % or less of Fe, with Si localized in the surface thereof is used.

Embodiments of synthetic garnet materials having advantageous properties, especially for below resonance frequency applications, are disclosed herein. In particular, embodiments of the synthetic garnet materials can have high Curie temperatures and dielectric constants while maintaining low magnetization. These materials can be incorporated into isolators and circulators, such as for use in telecommunication base stations.

A Co.sub.2Z hexaferrite composition is provided containing molybdenum and one or both of barium and strontium, having the formula (Ba.sub.2Sr.sub.(3-Z)Co.sub.(2+X))Mo.sub.xFe.sub.(y-2x)O.sub.41 where x=0.01 to 0.20; y=20 to 24; and z=0 to 3. The composition can exhibit high permeabilities and equal or substantially equal values of permeability and permittivity while retaining low magnetic and dielectric loss tangents and loss factors. The composition is suitable for high frequency applications such as ultrahigh frequency and microwave antennas and other devices.

Preparation, characterization, and an electrochemical study of Mg.sub.0.1V.sub.2O.sub.5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage 3.2 Volts with an energy density 800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.

The present invention describes a lithium-substituted magnesium ferrite material based hydroelectric cell and process for preparation thereof. A novel galvanic cell process of generating electric current in distilled water by lithium substituted magnesium ferrite hydroelectric cell has been developed. A synthesis process of ferrite pellet having zinc anode and silver inert electrode has been developed. The material splits water molecules and conducts ions within porous ferrite. Split ions electrochemically react with electrodes and form zinc hydroxide at anode and hydrogen gas at silver electrode. This hydroelectric cell has generated 5 mA short circuit current and 950 mV open cell voltage. Current increased to 20 mA by thermally deposited Zn electrode on a ferrite pellet. The cell is very economical and highly sensitive towards electrolysis of water molecules. It is a green source for producing energy and has a potential to excel from existing electrochemical batteries.

A production method for metal oxide particles includes: obtaining precursor particles of a metal oxide by performing a synthesis reaction of the precursor particles in the presence of an organic compound; and converting the obtained precursor particles into metal oxide particles by heating an aqueous solution containing the precursor particles to 300 C. or higher and pressurizing the aqueous solution at a pressure of 20 MPa or higher.