A composite magnetic material has a plurality of grains having a magnetic ferrite phase, grain boundaries surrounding the grains, and a plurality of nanoparticles disposed at the grain boundaries. The nanoparticles of the composite material are both magnetic and electrically insulating, having a magnetic flux density of greater than about 100 mT and an electrical resistivity of at least about 10.sup.8 Ohm-cm. Also provided is a method of making the composite material. The material is useful for making inductor cores of electronic devices.

Method for manufacturing a composite material combining a metal oxide or metalloid based matrix suited for allowing light to pass, and a mineral pigment dispersed in the matrix, the method comprising a step of mixing the mineral pigment in powder form with the matrix in powder form, and a step of sintering of the mixture under sufficient pressure such that the densification temperature of the matrix under said pressure is below the breakdown temperature of the mineral pigment, where the sintering temperature is greater than or equal to the densification temperature of the matrix and below the breakdown temperature of the mineral pigment.

A multiphase fluorescent ceramic and a preparation method therefor. Spinel is provided in a multiphase fluorescent ceramic comprising an alumina matrix and fluorescent particles, the spinel is distributed between alumina grain boundaries, and the exciting light irradiated into the multiphase fluorescent ceramic can be scattered, thereby facilitating further improvement in the luminous efficiency of the multiphase fluorescent ceramic.

The present invention relates to a ferrite particle, containing a crystal phase component containing a perovskite crystal represented by the compositional formula:

RZrO.sub.3 (provided that R represents an alkaline earth metal element), and having an apparent density in a range represented by the following formula:

1.90≤Y≤2.45

provided that Y in the formula is the apparent density (g/cm.sup.3) of the ferrite particle.

Certain embodiments of the present disclosure relate to ceramic materials with high thermal shock resistance and high erosion resistance. In one embodiment, a ceramic material is formed from a composition comprising Al.sub.2O.sub.3, MgO, SiO.sub.2.

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.

The composite sintered body includes AlN and MgAl.sub.2O.sub.4. The open porosity of the composite sintered body is lower than 0.1%. The relative density of the composite sintered body is not lower than 99.5%. The total percentage of the AlN and the MgAl.sub.2O.sub.4 contained in the composite sintered body is not lower than 95 weight percentage and not higher than 100 weight percentage. The percentage of the MgAl.sub.2O.sub.4 contained in the composite sintered body is not lower than 15 weight percentage and not higher than 70 weight percentage. It is thereby possible to provide a high-density composite sintered body having high plasma corrosion resistance, high volume resistivity, and high thermal conductivity.

The MnZn ferrite material includes principal components and auxiliary components, where the principal components include: 52.5 mol % to 53.8 mol % of Fe.sub.2O.sub.3, 8.8 mol % to 12 mol % of ZnO, and the balance of MnO; the auxiliary components include: 0.35 wt % to 0.5 wt % of Co.sub.2O.sub.3, 0.03 wt % to 0.08 wt % of CaSiO.sub.3, 0.01 wt % to 0.04 wt % of Nb.sub.2O.sub.5, and 0.05 wt % to 0.12 wt % of TiO.sub.2 and RE elemental components; the RE elemental components include one or more from the group consisting of 0 wt % to 0.04 wt % of Gd.sub.2O.sub.3, 0 wt % to 0.02 wt % of HO.sub.2O.sub.3, and 0 wt % to 0.03 wt % of Ce.sub.2O.sub.3; the auxiliary components are all represented by a mass percentage relative to a total mass of the Fe.sub.2O.sub.3, the MnO, and the ZnO.

Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co.sup.+2 such that the relaxation peak associated with the Co.sup.+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.

A method of removing fluoride ion from waste liquid is provided, which includes providing a calcium source and a plurality of ceramic particles to a waste liquid containing fluoride ion for forming a plurality of calcium fluoride layers wrapping the ceramic particles. The calcium fluoride layers are connected to form a calcium fluoride bulk. The ceramic particles are embedded in the calcium fluoride bulk. The ceramic particles and the calcium fluoride bulk have a weight ratio of 1:4 to 1:20.