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.

Provided is an electromagnetic-wave absorbing sheet that can favorably absorb electromagnetic waves of high frequencies in a frequency band equal to or higher than the millimeter-wave band while having elasticity of elongating in an in-plane direction. The electromagnetic-wave absorbing sheet includes an electromagnetic-wave absorbing layer 1 that contains a magnetic iron oxide 1a that magnetically resonates in a frequency band equal to or higher than the millimeter-wave band as an electromagnetic-wave absorbing material and a rubber binder 1b. The electromagnetic-wave absorbing sheet has a maximum elongation percentage of an elastic region in one in-plane direction of 20% to 200%.

Provided is an electromagnetic-wave absorber composition and an electromagnetic-wave absorber that can favorably absorb a plurality of electromagnetic waves of different frequencies in a high frequency band in or above the millimeter-wave band. The electromagnetic-wave absorber composition includes a magnetic iron oxide that magnetically resonates at a high frequency in or above the millimeter-wave band and a resin binder. The electromagnetic-wave absorber composition has two or more extrema separated from each other on a differential curve obtained by differentiating a magnetic property hysteresis loop at an applied magnetic field intensity of from 16 kOe to 16 kOe. The electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer formed of the above-described electromagnetic-wave absorber composition.

Embodiments of a method for synthesizing water-soluble metal oxide nanoparticles are disclosed. In one embodiment, the method includes heating a first reaction mixture at a predetermined temperature for a predetermined time duration with continuous stirring to obtain a second reaction mixture that comprises water-soluble metal oxide nanoparticles of a first size. The first reaction mixture includes a reactant and a polyol. The method further includes adding a first predetermined amount of the reactant to the second reaction mixture to obtain a third reaction mixture. The method further includes heating the third reaction mixture at the predetermined temperature for the predetermined time duration with continuous stirring to obtain a fourth reaction mixture comprising water-soluble metal oxide nanoparticles of a second size. The reactant is Fe(acac).sub.3 and the polyol is diethylene glycol (DEG) for synthesizing water-soluble iron oxide nanoparticles.

Provided is a vanadium oxide film which shows substantially no hysteresis of resistivity changes due to temperature rising/falling, has a low resistivity at room temperature, has a large absolute value of the temperature coefficient of resistance, and shows semiconductor-like resistance changes in a wide temperature range. In the vanadium oxide film, a portion of the vanadium has been replaced by aluminum and copper, and the amount of substance of aluminum is 10 mol % based on the sum total of the amount of substance of vanadium, the amount of substance of aluminum, and the amount of substance of copper. This vanadium oxide film has a low resistivity, has a large absolute value of the temperature coefficient of resistance, and shows substantially no hysteresis of resistivity changes due to temperature rising/falling. This vanadium oxide film is produced by applying a mixture solution containing a vanadium organic compound, an aluminum organic compound, and a copper organic compound to a substrate, calcining the substrate at a temperature lower than the temperature at which the substrate decomposes, and irradiating the surface of the substrate onto which the mixture solution has been applied with ultraviolet light.

Provided is a vanadium oxide film which shows substantially no hysteresis of resistivity changes due to temperature rising/falling, has a low resistivity at room temperature, has a large absolute value of the temperature coefficient of resistance, and shows semiconductor-like resistance changes in a wide temperature range. In the vanadium oxide film, a portion of the vanadium has been replaced by aluminum and copper, and the amount of substance of aluminum is 10 mol % based on the sum total of the amount of substance of vanadium, the amount of substance of aluminum, and the amount of substance of copper. This vanadium oxide film has a low resistivity, has a large absolute value of the temperature coefficient of resistance, and shows substantially no hysteresis of resistivity changes due to temperature rising/falling. This vanadium oxide film is produced by applying a mixture solution containing a vanadium organic compound, an aluminum organic compound, and a copper organic compound to a substrate, calcining the substrate at a temperature lower than the temperature at which the substrate decomposes, and irradiating the surface of the substrate onto which the mixture solution has been applied with ultraviolet light.

The purpose of the present invention is to provide: a new magnetic material which exhibits high magnetic stability and excellent oxidation resistance and which can achieve both significantly higher saturation magnetization and lower coercive force than a conventional ferrite-based magnetic material by using a magnetic material obtained by nanodispersing -(Fe,M) phases and M component-enriched phases (here, the M component is at least one component selected from among Zr, Hf, V, Nb, Ta, Cr, Mo, W, Cu, Zn and Si); and a method for producing same. This magnetic material powder exhibits high moldability, and is such that -(Fe, M) phases and M-enriched phases are nanodispersed by chemically reducing M-ferrite nanoparticles, which are obtained by means of wet synthesis, in hydrogen and utilizing phase separation by means of a disproportionation reaction while simultaneously carrying out grain growth. Furthermore, a solid magnetic material is obtained by sintering this powder.

MnZn ferrite particles according to the present invention contain 44-60% by mass of Fe, 10-16% by mass of Mn and 1-11% by mass of Zn. The ferrite particles are single crystal bodies having an average particle diameter of 1-2,000 nm, and have polyhedral particle shapes, while having an average sphericity of 0.85 or more but less than 0.95.

MnZn ferrite particles according to the present invention contain 44-60% by mass of Fe, 10-16% by mass of Mn and 1-11% by mass of Zn. The ferrite particles are single crystal bodies having an average particle diameter of 1-2,000 nm, and have polyhedral particle shapes, while having an average sphericity of 0.85 or more but less than 0.95.

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.