There is provided a group III nitride laminate, including: a substrate comprised of silicon carbide; a first layer comprised of aluminum nitride and formed on the substrate; a second layer comprised of gallium nitride and formed on the first layer; and a third layer formed on the second layer and comprised of group III nitride having an electron affinity lower than that of the gallium nitride which is comprised in the second layer, the second layer having a thickness of less than 500 nm, the second layer containing iron at a concentration of less than 1×10.sup.17/cm.sup.3, and the second layer containing carbon at a concentration of less than 1×10.sup.17/cm.sup.3.

A reaction-bonded silicon carbide (SiC) body is produced by: providing a preform including ceramic elements and carbon, and one or more surface features; providing a powder which includes diamond particles and carbon; locating the powder in the surface feature(s); and infiltrating the preform and the powder with molten silicon (Si) to form reaction-bonded SiC in the preform, and to form reaction-bonded SiC coatings on the diamond particles. The present disclosure also relates to a device/component which includes: a main body portion and discrete elements located at least partially within the main body portion. The main body portion may include reaction-bonded SiC and Si, but not diamond, while the discrete elements include diamond particles, reaction-bonded SiC coatings surrounding the diamond particles, and Si. According to the present disclosure, diamond may be advantageously located only where it is needed.

A ceramic composite can include a first ceramic phase and a second ceramic phase. The first ceramic phase can include a silicon carbide. The second phase can include a boron carbide. In an embodiment, the silicon carbide in the first ceramic phase can have a grain size in a range of 0.8 to 200 microns. The first phase, the second phase, or both can further include a carbon. In another embodiment, at least one of the first ceramic phase and the second ceramic phase can have a median minimum width of at least 5 microns.

A ceramic composite can include a first ceramic phase and a second ceramic phase. The first ceramic phase can include a silicon carbide. The second phase can include a boron carbide. In an embodiment, the silicon carbide in the first ceramic phase can have a grain size in a range of 0.8 to 200 microns. The first phase, the second phase, or both can further include a carbon. In another embodiment, at least one of the first ceramic phase and the second ceramic phase can have a median minimum width of at least 5 microns.

A process for manufacturing continuous ceramic tape includes steps of heating a ceramic feedstock to a molten state and spraying molten droplets of the feedstock onto a deposition surface. The method further includes forming a ceramic coating on the deposition surface by accumulating the droplets, which solidify and are directly bonded to one another. The deposition surface is non-stick with respect to the ceramic coating such that the coating may be peeled off of the deposition surface as a continuous ceramic tape, without fracture. Additionally, in embodiments, the deposition surface is removed by running the deposition over a bending edge, chemically stripping or dissolving the deposition surface, or burning the deposition surface.

A process for manufacturing continuous ceramic tape includes steps of heating a ceramic feedstock to a molten state and spraying molten droplets of the feedstock onto a deposition surface. The method further includes forming a ceramic coating on the deposition surface by accumulating the droplets, which solidify and are directly bonded to one another. The deposition surface is non-stick with respect to the ceramic coating such that the coating may be peeled off of the deposition surface as a continuous ceramic tape, without fracture. Additionally, in embodiments, the deposition surface is removed by running the deposition over a bending edge, chemically stripping or dissolving the deposition surface, or burning the deposition surface.

A dielectric ceramic composition includes a barium titanate (BaTiO.sub.3)-based base material main ingredient and an accessory ingredient, the accessory ingredient including dysprosium (Dy) and praseodymium (Pr) as first accessory ingredients. A content of the Pr satisfies 0.233 mol≤Pr≤0.699 mol, based on 100 mol of the barium titanate base material main ingredient.

A dielectric ceramic composition includes a barium titanate (BaTiO.sub.3)-based base material main ingredient and an accessory ingredient, the accessory ingredient including dysprosium (Dy) and praseodymium (Pr) as first accessory ingredients. A content of the Pr satisfies 0.233 mol≤Pr≤0.699 mol, based on 100 mol of the barium titanate base material main ingredient.

A method for manufacturing a multilayer ceramic electronic device includes punching out a ceramic sheet by one of left and right side surfaces of a laminated body so as to form a side margin part on the one of the left and right side surfaces of said laminated body; and punching out another ceramic sheet by another of the left and right side surfaces of the laminated body so as to form a side margin part on the another of the left and right side surfaces of said laminated body, thereby forming a ceramic main body having the laminated body and the pair of side margin parts that respectively cover the left and right side surfaces of the laminated body. The width W is greater than the length L in the multilayer ceramic electronic device.

The method includes forming an inner monolithic layer from crystals of beta phase stoichiometric silicon carbide on a carbon substrate in the form of a rod by chemical methylsilane vapor deposition in a sealed tubular hot-wall CVD reactor. The method further includes forming a central composite layer over the inner monolithic layer by twisting continuous beta phase stoichiometric silicon carbide fibers into tows, transporting the tows to a braiding machine, and forming a reinforcing thread framework. A pyrocarbon interface coating is built up by chemical methane vapor deposition in a sealed tubular hot-wall CVD reactor. Then, a matrix is formed by chemical methylsilane vapor deposition in the reactor. A protective outer monolithic layer is formed from crystals of beta phase stoichiometric silicon carbide over the central composite layer by chemical methylsilane vapor deposition in a CVD reactor. And then the carbon substrate is removed from the fabricated semi-finished product.