The present invention provides a silicon nitride sintered substrate capable of reducing contamination caused by a boron nitride powder or the like used as a releasing agent and problems in bonding strength and dielectric strength at the time of laminating metal layers or the like, where the contamination is caused by a network structure provided by a silicon nitride crystal formed on the surface of the substrate in an unpolished state after sintering a silicon nitride powder. The silicon nitride substrate in an unpolished state after sintering is a silicon nitride sintered substrate where a cumulative volume of pores having a diameter in a range of 1 to 10 μm is not more than 7.0'10.sup.−5 mL/cm.sup.2 in a measurement by a mercury porosimetry. Preferably, Ra of the surface is not more than 0.6 μm and arithmetic mean peak curvature (Spc) of a peak is not more than 4.5 [l/mm].

This disclosure provides systems, methods, and apparatus related to boron nitride nanomaterials. In one aspect, a method includes generating a directed flow of plasma. A boron-containing species is introduced to the directed flow of the plasma. Boron nitride nanostructures are formed in a chamber. In another aspect, a method includes generating a directed flow of plasma using nitrogen gas. A boron-containing species is introduced to the directed flow of the plasma. The boron-containing species can consist of boron powder, boron nitride powder, and/or boron oxide powder. Boron nitride nanostructures are formed in a chamber, with a pressure in the chamber being about 3 atmospheres or greater.

Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB.sub.2O.sub.4. CaB.sub.2O.sub.4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB.sub.2O.sub.4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.

An insert of the present disclosure includes a boron nitride sintered body including a first surface. In a transmission X-ray diffraction of a cross section of the boron nitride sintered body vertical to the first surface, X-ray intensity at a top of a 111 diffraction peak of cubic boron nitride in a direction vertical to the first surface is IcBN(111)v. X-ray intensity at a top of a 002 diffraction peak of compressed boron nitride is IhBN(002)v. X-ray intensity at a top of a 111 diffraction peak of the cubic boron nitride in a direction parallel to the first surface is IcBN(111)h. X-ray intensity at a top of a 002 diffraction peak of the compressed boron nitride is IhBN(002)h. A compressed boron nitride content value obtained from these X-ray intensities is larger than 0.005. A cubic orientation value is larger than 0.5, and a compressed boron nitride orientation value is larger than the cubic orientation value.

Composite multilayered material compositions are provided which contain one or more hexagonal boron nitride (hBN)-containing layers, together with layers comprising optional polymeric binders, glass fibers, magneto-ceramic materials, and a super-hydrophobic outer coating. Methods are provided for making the composite materials and products containing them. The composite materials are useful for making radomes and other coverings for electronic components and equipment.

This ferrite sintered magnet comprises metallic elements at an atomic ratio represented by formula (1):
Ca.sub.1-w-xR.sub.wSr.sub.xFe.sub.zCo.sub.m  (1) in formula (1), R is at least one element selected from the group consisting of rare-earth elements and Bi, and R comprises at least La, in formula (1), w, x, z and m satisfy formulae (2) to (5):
0.360≤w≤0.420  (2)
0.110≤x≤0.173  (3)
8.51≤z≤9.71  (4)
0.208≤m≤0.269  (5), and in a section parallel to an axis of easy magnetization, when the number of total ferrite grains is N and the number of ferrite grains having a stacking fault is n, 0≤n/N≤0.20 is satisfied.

This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A.sub.1-xR.sub.x(Fe.sub.12-yMe.sub.y).sub.z, (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. The invention makes it possible to achieve a ferrite magnet with increased Br.

One aspect of the present invention is a method for producing a composite, including a step of placing a porous boron nitride sintered body immersed in a resin composition under a pressurized condition and then placing the boron nitride sintered body immersed in the resin composition under a pressure condition lower than the pressurized condition, wherein the step is repeated a plurality of times.

The present invention provides a ferrite sintered magnet comprising (1) main phase grains containing a ferrite having a hexagonal structure, (2) two-grain boundaries formed between two of the main phase grains, and (3) multi-grain boundaries surrounded by three or more of the main phase grains. The above ferrite sintered magnet comprises Ca, R, Sr, Fe and Co, with R being at least one element selected from the group consisting of rare earth elements and Bi, and comprising at least La. The number Nm of the above main phase grains and the number Ng of the above multi-grain boundaries in the cross section including the direction of the easy magnetization axis of the above ferrite sintered magnet satisfy the formula (1A):
50%≤Nm/(Nm+Ng)≤65%  (1A).

Disclosed herein is a material suitable for the adsorption, storage and release of volatile organic compounds comprising: a porous thin film layer formed from nanosheets of one or more MXenes.