A silicon carbide single crystal wafer and a preparation method therefor, a silicon carbide crystal and a preparation method therefor, and a semiconductor device. The surface of the silicon carbide single crystal wafer is such that an included angle between a normal direction and a c direction is 0-8 degrees, and aggregated dislocations on the silicon carbide single crystal wafer are less than 300/cm.sup.2; the aggregated dislocation is a dislocation aggregated condition in which the distance between the geometric centers of any two corrosion pits in the corrosion pits obtained after corrosion of melted KOH is less than 80 microns. Even if the dislocation density is relatively high, the aggregated dislocation density is relatively small, thereby increasing the yield of a silicon carbide-based devices.

A silicon carbide single crystal wafer and a preparation method therefor, a silicon carbide crystal and a preparation method therefor, and a semiconductor device. The surface of the silicon carbide single crystal wafer is such that an included angle between a normal direction and a c direction is 0-8 degrees, and aggregated dislocations on the silicon carbide single crystal wafer are less than 300/cm.sup.2; the aggregated dislocation is a dislocation aggregated condition in which the distance between the geometric centers of any two corrosion pits in the corrosion pits obtained after corrosion of melted KOH is less than 80 microns. Even if the dislocation density is relatively high, the aggregated dislocation density is relatively small, thereby increasing the yield of a silicon carbide-based devices.

Various embodiments may provide an electromechanical responsive film. The electromechanical responsive film may include a composition including sodium (Na), potassium (K), niobium (Nb) and oxygen (O). The composition may have a formula (Na.sub.xK.sub.y)NbO.sub.3-δ, wherein 0≤x<1, wherein 0≤y<1, and wherein 0<x+y<1. The composition may satisfy at least one condition selected from a group consisting of a first condition of (x+y+4)/2≤(3−δ)≤(x+y+5)/2 and a second condition of 0<δ<1.

Apparatus and associated methods relate to forming an epitaxial layer of aluminum on an aluminum-nitride compound. The aluminum is epitaxially grown on the crystalline aluminum-nitride compound by maintaining temperature of a crystalline aluminum-nitride compound below a cluster-favoring temperature threshold within a vacuum chamber. Then, the crystalline aluminum-nitride compound is exposed to atoms of elemental aluminum for a predetermined time duration. The aluminum is epitaxially grown in this fashion for a predetermined time duration so as to produce a layer of epitaxial aluminum of a predetermined thickness. Such epitaxially-grown mono-crystalline aluminum has a lower resistivity than poly-crystalline aluminum.

An Fe—Co—Al alloy magnetic thin film contains, in terms of atomic ratio, 20% to 30% Co and 1.5% to 2.5% Al. The Fe—Co—Al alloy magnetic thin film has a crystallographic orientation such that the (100) plane is parallel to a substrate surface and the <100> direction is perpendicular to the substrate surface. The Fe—Co—Al alloy magnetic thin film has good magnetic properties, that is, a magnetization of 1440 emu/cc or more, a coercive force of less than 100 Oe, a damping factor of less than 0.01, and an FMR linewidth ΔH at 30 GHz of less than 70 Oe.

An Fe—Co—Al alloy magnetic thin film contains, in terms of atomic ratio, 20% to 30% Co and 1.5% to 2.5% Al. The Fe—Co—Al alloy magnetic thin film has a crystallographic orientation such that the (100) plane is parallel to a substrate surface and the <100> direction is perpendicular to the substrate surface. The Fe—Co—Al alloy magnetic thin film has good magnetic properties, that is, a magnetization of 1440 emu/cc or more, a coercive force of less than 100 Oe, a damping factor of less than 0.01, and an FMR linewidth ΔH at 30 GHz of less than 70 Oe.

A single crystal multilayer low-loss optical component including first and second layers made from dissimilar materials, with the materials including the first layer lattice-matched to the materials including the second layer. The first and second layers are grown epitaxially in pairs on a growth substrate to which the materials of the first layer are also lattice-matched, such that a single crystal multilayer optical component is formed. The optical component may further include a second substrate to which the layer pairs are wafer bonded after being removed from the growth substrate.

The present disclosure relates to a graphene composite and a method of manufacturing the same, and a graphene composite according to an exemplary embodiment includes: a substrate; a first thin film positioned on the substrate; and a second thin film positioned on the first thin film, in which the first thin film includes graphene, and the second thin film includes at least any one of VSe.sub.2, VS.sub.2, VTe.sub.2, TaS.sub.2, TaSe.sub.2, NbS.sub.2, NbSe.sub.2, TiS.sub.2, TiSe.sub.2, TiTe.sub.2, ReS.sub.2, and ReSe.sub.2.

A crystal raw material loading device and a crystal growth device includes a plurality of bearing units which are arranged adjacent to each other horizontally in turn, and the multiple bearing units include a first bearing unit arranged at one end of a small plane far away from the seed crystal bearing device. Along the direction from one end of the small plane far away from the seed crystal to one end of the small plane close to the seed crystal, from the first bearing unit to the bearing unit on the side of the small plane close to the seed crystal, the height of the raw material that can be carried by each bearing unit is reduced in turn.

A crystal raw material loading device and a crystal growth device includes a plurality of bearing units which are arranged adjacent to each other horizontally in turn, and the multiple bearing units include a first bearing unit arranged at one end of a small plane far away from the seed crystal bearing device. Along the direction from one end of the small plane far away from the seed crystal to one end of the small plane close to the seed crystal, from the first bearing unit to the bearing unit on the side of the small plane close to the seed crystal, the height of the raw material that can be carried by each bearing unit is reduced in turn.