A magnetic material and method prepares high-performance composite ferrite for a self-biased circulator. The preparation method includes: (1) preparing BaM ferrite initial powder and NiCuZnSn ferrite initial powder, respectively; (2) mixing the BaM ferrite initial powder, the NiCuZnSn ferrite initial powder and deionized water uniformly in proportion, performing ball milling in a high-energy ball mill, and then obtaining mixed powder after primary pre-sintering, secondary pre-sintering and secondary ball milling; and (3) obtaining the high-performance composite ferrite for the self-biased circulator by a low-temperature magnetic field orientation forming technology and magnetic field heat treatment. According to the present invention, the saturated magnetization intensity is enhanced better by compounding the BaM ferrite powder and the NiCuZnSn ferrite powder and through a high-energy ball milling technology, the low-temperature magnetic field orientation forming technology and the magnetic field heat treatment technology, thereby improving the microstructure and the magnetic characteristic of bi-phase composite ferrite.

Novel compounds having a thortveitite-related structure are disclosed. The compounds may be colored and may be useful as pigments. The compounds are durable with respect to an acid stability test that indicates that the pigments will not substantially change color when exposed to weak acids, such as rain. The compounds disclosed herein typically inexpensive to synthesize from earth-abundant, environmentally-friendly elements or minerals, and therefore are advantageous over existing pigments in the art.

Magnetic nanoparticles and synthesis of synthesis are described.

Methods, systems, and devices are disclosed for fabricating and implementing optically absorbing coatings. In one aspect, an optically selective coating includes a substrate formed of a solar energy absorbing material, and a nanostructure material formed over the substrate as a coating capable of absorbing solar energy in a selected spectrum and reflecting the solar energy in another selected spectrum. A concentrating solar power (CSP) system includes heat transfer fluids (HTFs); thermal energy storage system (TES); and solar receivers in communication with HTFs and including a light absorbing coating layer based on cobalt oxide nanoparticles.

The present invention discloses a process to treat a ferrite based catalyst useful in the oxidative dehydrogenation of monololefins and diolefins which process includes a preheat step prior to use of the catalyst in the OXO-D reactor. The catalyst is preferably a zinc ferrite catalyst for the production of butadiene. It has been observed that substantially no nitrogen oxide emissions result from the use of this treated catalyst in the reactor unit during the oxidative dehydrogenation reaction.

The present invention generally relates to a method for synthesizing dysprosium-doped copper-zinc ferrite nanomaterials with enhanced structural and functional properties. The method comprises dissolving stoichiometric quantities of copper nitrate trihydrate, zinc nitrate hexahydrate, iron nitrate nonahydrate, and dysprosium nitrate hexahydrate in distilled water to prepare an oxidizer solution. A fuel mixture is separately prepared using urea and glucose in equal proportions by weight. The oxidizer and fuel mixtures are combined in 1:1 ratio, calculated based on their respective oxidizing and reducing valencies, to form a homogeneous precursor solution. This solution is stirred thoroughly for about one hour and subsequently transferred to a Pyrex dish. The dish is placed in a muffle furnace preheated to approximately 450 C., where the solution undergoes a self-sustained combustion reaction, yielding a fine, porous Cu.sub.0.5Zn.sub.0.5Dy.sub.xFe.sub.2-xO.sub.4 ferrite powder within 20 minutes. The resultant powder is ground to achieve uniform particle distribution suitable for advanced applications.

A rhombohedral Zn.sub.2SiO.sub.4/cubic ZnFe.sub.2O.sub.4/hexagonal SiO.sub.2/C nanocomposite material includes a rhombohedral zinc orthosilicate (Zn.sub.2SiO.sub.4) phase, a cubic zinc ferrite (ZnFe.sub.2O.sub.4) phase, and a hexagonal silicon dioxide (SiO.sub.2) phase. The rhombohedral Zn.sub.2SiO.sub.4/cubic ZnFe.sub.2O.sub.4/hexagonal SiO.sub.2/C nanocomposite material exhibits a morphology including spherical microscale particles with an average diameter ranging from 0.8 micrometer (m) to 1.8 m and irregular nanoscale aggregates with an average diameter ranging from 50 nanometer (nm) to 110 nm. The rhombohedral Zn.sub.2SiO.sub.4/cubic ZnFe.sub.2O.sub.4/hexagonal SiO.sub.2/C nanocomposite material has an adsorption capacity for basic fuchsin dye of greater than or equal to 140 milligrams per gram (mg/g). Furthermore, a method for producing the rhombohedral Zn.sub.2SiO.sub.4/cubic ZnFe.sub.2O.sub.4/hexagonal SiO.sub.2/C nanocomposite material includes calcination of metal precursors.