Abstract: The present disclosure is directed to methods of Quantum Spin Engineering of spinel superparamagnetic ferrite nanoparticles (SMFNs) for MRI contrast agents and for magnetohyperthermia agents. Using the methods herein, the magnetic properties of the SMFNs can be controlled by changing the amount of 3d-transition element cations having unpaired electrons in the 3d orbital that occupy the octahedral sites of the spinel crystal form, to form mixed spinels, while anions in the spinels can be utilized to magnetically couple the cations utilizing intra-crystalline angles determined by ion sizes and crystal structure, and further tuning of other critical parameters is provided. The mixed spinels disclosed herein provide enhanced MRI contrast agents and improved magnetohyperthermia agents with lower toxicity and safety concerns, while the production methods disclosed herein have lower cost.

Abstract: A composite material can include a grain component and a nanostructured grain boundary component. The nanostructured grain boundary component can be insulating and magnetic, so as to provide greater continuity of magnetization of the composite material. The grain component can have an average grain size of about 0.5-50 micrometers. The grain boundary component can have an average grain size of about 1-100 nanometers. The nanostructured magnetic grain boundary material has a magnetic flux density of at least about 250 mT. The grain component can comprise MnZn ferrite particles. The nanostructured grain boundary component can comprise NiZn ferrite nanoparticles. Core components and systems thereof can be manufactured from the composite material.

Abstract: A composite material can include a grain component and a nanostructured grain boundary component. The nanostructured grain boundary component can be insulating and magnetic, so as to provide greater continuity of magnetization of the composite material. The grain component can have an average grain size of about 0.5-50 micrometers. The grain boundary component can have an average grain size of about 1-100 nanometers. The nanostructured magnetic grain boundary material has a magnetic flux density of at least about 250 mT. The grain component can comprise MnZn ferrite particles. The nanostructured grain boundary component can comprise NiZn ferrite nanoparticles. Core components and systems thereof can be manufactured from the composite material.

Abstract: A crystalline ferromagnetic material based upon nanoscale cobalt carbide particles and a method of manufacturing the material via a polyol reaction are disclosed. The crystalline ferromagnetic cobalt carbide nanoparticles are useful for high performance permanent magnet applications. The processes are extendable to other carbide phases. Fe- and FeCo-carbides are realizable by using as precursor salts Fe-, Co-, and mixtures of Fe- and Co-salts, such as acetates, nitrates, chlorides, bromides, citrates, and sulfates. The materials include mixtures and/or admixtures of cobalt carbides, as both Co2C and Co3C phases. Mixtures may be a collection of independent particles of Co2C and Co3C or a collection of particles which consist of an intimate combination of Co2C and Co3C phases within individual particles. The relative proportions of these two phases and the morphology of each phase contribute to their permanent magnet properties, particularly at room temperature to over 400 K.

Abstract: A composition of a crystalline ferromagnetic material based upon nanoscale cobalt carbide particles and to a method of manufacturing the ferromagnetic material of the invention via a polyol reaction are disclosed. The crystalline ferromagnetic cobalt carbide nanoparticles of the invention are useful for high performance permanent magnet applications. The processes according to the invention are extendable to other carbide phases, for example to Fe-, FeCo-carbides. Fe- and FeCo-carbides are realizable by using as precursor salts Fe-, Co-, and mixtures of Fe- and Co-salts, such as acetates, nitrates, chlorides, bromides, citrates, and sulfates, among others. The materials according to the invention include mixtures and/or admixtures of cobalt carbides, as both Co2C and Co3C phases. Mixtures may take the form of a collection of independent particles of Co2C and Co3C or as a collection of particles which consist of an intimate combination of Co2C and Co3C phases within individual particles.

Abstract: A broadband integrated circulator antenna (BICA) module for receiving and transmitting signals with high efficiency and high gain. The BICA can have a bandwidth of over 70% of a radar band and can operate in frequencies from UHF to S-band and above. The BICA has a stack configuration that includes a low profile antenna, a reflecting layer or a metamaterial substrate layer, and a circulator. The circulator is placed proximal to antenna, which greatly reduces the size of the BICA. The circulator can be a stripline Y-junction ferrite circulator and the antenna can be a coaxial center fed bow-tie antenna. The reflecting layer or metamaterial substrate layer can comprise electronic bandgap metamaterial and a high permeability ferrite substrate. The high permeability ferrite substrate can be cobalt substituted Z-type barium hexaferrite.

Abstract: A composite material can include a grain component and a nanostructured grain boundary component. The nanostructured grain boundary component can be insulating and magnetic, so as to provide greater continuity of magnetization of the composite material. The grain component can have an average grain size of about 0.5-50 micrometers. The grain boundary component can have an average grain size of about 1-100 nanometers. The nanostructured magnetic grain boundary material has a magnetic flux density of at least about 250 mT. The grain component can comprise MnZn ferrite particles. The nanostructured grain boundary component can comprise NiZn ferrite nanoparticles. Core components and systems thereof can be manufactured from the composite material.

Abstract: A composition of a crystalline ferromagnetic material based upon nanoscale cobalt carbide particles and to a method of manufacturing the ferromagnetic material of the invention via a polyol reaction are disclosed. The crystalline ferromagnetic cobalt carbide nanoparticles of the invention are useful for high performance permanent magnet applications. The processes according to the invention are extendable to other carbide phases, for example to Fe-, FeCo-carbides. Fe- and FeCo-carbides are realizable by using as precursor salts Fe-, Co-, and mixtures of Fe- and Co-salts, such as acetates, nitrates, chlorides, bromides, citrates, and sulfates, among others. The materials according to the invention include mixtures and/or admixtures of cobalt carbides, as both Co2C and Co3C phases. Mixtures may take the form of a collection of independent particles of Co2C and Co3C or as a collection of particles which consist of an intimate combination of Co2C and Co3C phases within individual particles.

Abstract: A broadband integrated circulator antenna (BICA) module for receiving and transmitting signals with high efficiency and high gain. The BICA can have a bandwidth of over 70% of a radar band and can operate in frequencies from UHF to S-band and above. The BICA has a stack configuration that includes a low profile antenna, a reflecting layer or a metamaterial substrate layer, and a circulator. The circulator is placed proximal to antenna, which greatly reduces the size of the BICA. The circulator can be a stripline Y-junction ferrite circulator and the antenna can be a coaxial center fed bow-tie antenna. The reflecting layer or metamaterial substrate layer can comprise electronic bandgap metamaterial and a high permeability ferrite substrate. The high permeability ferrite substrate can be cobalt substituted Z-type barium hexaferrite.

Abstract: A semiconductor device including a ferrite layer, a widebandgap semiconductor material layer, and a buffer layer. The buffer layer comprises an interweaving of MgO and BaM. In addition the buffer layer allows a gradual reduction of the interfacial stress, and mediates the strain between a silicon substrate and a ferrite layer of the device. In addition, the buffer layer allows for high crystal alignment resulting in high crystal quality and thereby producing a low microwave loss semiconductor device. The buffer layer also minimizes chemical interdiffusion of atoms between the substrate and the ferrite layer.

Abstract: A method of producing a relatively-thick film of a magnetic material on a substrate for use in microwave and millimeter wave devices is disclosed. The method includes preparing a wet paste comprising a binder material, glass frit, and a finely-grained magnetic material; applying the wet paste over a stencil, template or mask disposed on the substrate, to form a film on a surface of the substrate; drying the wet paste within an applied magnetic field, to vaporize fluid and organic compounds in the binder material and to produce a desired magnetic orientation in the magnetic film; and sintering the magnetic film. Hot pressing the magnetic film during sintering by adding weight on the film improves density.

Abstract: A method for making monodispersed magnetic nanoparticles of nickel zinc ferrite (NZFO) at room temperature by mixing together two micelle solutions. The first micelle solution comprises zinc, nickel, and iron metal salts; a surfactant; and a hydrocarbon. The second micelle solution comprises and aqueous hydroxide, a surfactant, and a hydrocarbon. After mixing the two micelle solutions, the ferrite precipitates.

Abstract: A method for making monodispersed magnetic nanoparticles of nickel zinc ferrite (NZFO) at room temperature by mixing together two micelle solutions. The first micelle solution comprises zinc, nickel, and iron metal salts; a surfactant; and a hydrocarbon. The second micelle solution comprises an aqueous hydroxide, a surfactant, and a hydrocarbon. After mixing the two micelle solutions, the ferrite precipitates.

Abstract: Nanoparticles of a mixed oxide precursor are reduced to form particles of a anostructured metastable alloy having a majority metal and a minority metal. Additional heating enriches the surfaces of the particles with respect to the minority metal, thus forming a coating on the particle core. This coating has a higher atomic ratio of minority to majority metal than found in the precursor. The nanostructured metastable alloys may then be oxidized to form nanoparticles having a coating of the oxide of the minority metal and a core of the majority metal or an oxide of the majority metal. The majority metal may be, for example, copper. The minority metal may be, for example, cobalt.

Abstract: Oxidation resistant particles composed of copper and at least one metal hng a valence of +2 or +3 and having an intermediate lattice energy for the metal in its hydroxide form. The metal is selected from nickel, cobalt, iron, manganese, cadmium, zinc, tin, magnesium, calcium and chromium. In one embodiment, the phases of copper and at least one metal in the particles are separate and the concentration of the metal is greater near the surface of the particles than inwardly thereof. Process for making the oxidation resistant copper particles includes the steps of dissolving a copper salt and a salt of at least one of the metals in a suitable solvent or diluent; forming primary particles of copper and at least one metal in basic form by mixing a base and the salt solution; separating, washing and drying the primary particles; reducing the primary particles to metallic form; and heat treating the particles in metallic form at an elevated temperature.

Abstract: Oxidation resistant particles composed of copper and at least one metal having a valence of +2 or +3 and having an intermediate lattice energy for the metal in its hydroxide form. The metal is selected from nickel, cobalt, iron, manganese, cadmium, zinc, tin, magnesium, calcium and chromium. In one embodiment, the phases of copper and at least one metal in the particles are separate and the concentration of the metal is greater near the surface of the particles than inwardly thereof. Process for making the oxidation resistant copper particles includes the steps of dissolving a copper salt and a salt of at least one of the metals in a suitable solvent or diluent; forming primary particles of copper and at least one metal in basic form by mixing a base and the salt solution; separating, washing and drying the primary particles; reducing the primary particles to metallic form; and heat treating the particles in metallic form at an elevated temperature.