An MBE system is disclosed for eliminating the excess flux in an MBE growth chamber before growth, during growth or growth interruption, and/or after growth by evaporating getter material from an effusion evaporator to the cold panel. The cold panel can be the cryopanel of the MBE growth chamber or a cold panel in an attached chamber. Said MBE system includes the cyropanel in the MBE growth chamber or a cold panel in the chamber attached to the MBE growth chamber. With a proper process such as cooling the cold panel, loading a substrate for the MBE process, providing necessary flux for the MBE growth, heating the effusion evaporator and opening the shutter for the evaporator to get the getter material flux onto the said panel, the excess flux will be eliminated. The cross contamination of the grown layer is then avoided.

A silicon carbide wafer is provided, wherein within a range area of 5 mm from an edge of the silicon carbide wafer, there are no low angle grain boundaries formed by clustering of basal plane dislocation defects, and the silicon carbide wafer has a bowing of less than 15 μm.

A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm.sup.−2, a threading screw dislocation density of not more than 1×10.sup.4 cm.sup.−2, a threading edge dislocation density of not more than 1×10.sup.4 cm.sup.−2, a basal plane dislocation density of not more than 1×10.sup.4 cm.sup.−2, a stacking fault density of not more than 0.1 cm.sup.−1, a conductive impurity concentration of not less than 1×10.sup.18 cm.sup.−3, a residual impurity concentration of not more than 1×10.sup.16 cm.sup.−3, and a secondary phase inclusion density of not more than 1 cm.sup.−3.

A biomedical implant (16, 18) is formed from magnesium (Mg) single crystal (10). The biomedical implant (16, 18) may be biodegradable. The biomedical implant (16, 18) may be post treated to control the mechanical properties and/or corrosion rate thereof said Mg single crystal (10) without changing the chemical composition thereof. A method of making a Mg single crystal (10) for biomedical applications includes filling a single crucible (12) with more than one chamber with polycrystalline Mg, melting at least a portion of said polycrystalline Mg, and forming more than one Mg single crystal (10) using directional solidification.

A nanopowder continuous production device for improving nanopowder collection efficiency is proposed. In one aspect, the device includes a reaction chamber evaporating a raw material using a plasma electrode and a crucible, and a raw material supplier connected to a first side of the reaction chamber and supplying the raw material to the reaction chamber. The device may also include a conveying film moving along a closed loop while capturing and conveying evaporated raw material or crystallized nanopowder at an upper portion in the reaction chamber, and a collector connected to a second side of the reaction chamber and collecting the nanopowder conveyed by the conveying film. The collector may include a first capturer having a scrapper disposed at an end of the conveying film and tensioners elastically supporting the scrapper, and a first side of the scrapper is in close contact with the conveying film.

A silicon-carbide volume monocrystal is produced with a specific electrical resistance of at least 10.sup.5 Ωcm. An SiC growth gas phase is generated in a crystal growing area of a crucible. The SiC volume monocrystal grows by deposition from the SiC growth gas phase. The growth material is transported from a supply area inside the growth crucible to a growth boundary surface of the growing monocrystal. Vanadium is added to the crystal growing area as a doping agent. A temperature at the growth boundary surface is set to at least 2250° C. and the SiC volume monocrystal grows doped with a vanadium doping agent concentration of more than 5.Math.10.sup.17 cm.sup.−3. The transport of material from the SiC supply area to the growth boundary surface is additionally influenced. The growing temperature at the growth boundary surface and the material transport to the growth boundary surface are influenced largely independently of one another.

A method for making a transition metal dichalcogenide crystal having a chemical formula represented as MX.sub.2 is provided, wherein M represents a central transition metal element, and X represents a chalcogen element. The method includes providing a MX.sub.2 polycrystalline powder, a MX.sub.2 seed crystal, and a transport medium. The MX.sub.2 polycrystalline powder and the transport medium are placed in a first reaction chamber. The first reaction chamber and the MX.sub.2 seed crystal are placed in a second reaction chamber having a source end and a deposition end opposite to the source end. The first reaction chamber is placed at the source end, and the MX.sub.2 seed crystal is placed at the deposition end.

An SiC crystal (10) has Fe concentration not higher than 0.1 ppm and Al concentration not higher than 100 ppm. A method of manufacturing an SiC crystal includes the following steps. SiC powders for polishing are prepared as a first source material (17). A first SiC crystal (11) is grown by sublimating the first source material (17) through heating and precipitating an SiC crystal. A second source material (12) is formed by crushing the first SiC crystal (11). A second SiC crystal (14) is grown by sublimating the second source material (12) through heating and precipitating an SiC crystal. Thus, an SiC crystal and a method of manufacturing an SiC crystal capable of achieving suppressed lowering in quality can be obtained.

An SiC crystal (10) has Fe concentration not higher than 0.1 ppm and Al concentration not higher than 100 ppm. A method of manufacturing an SiC crystal includes the following steps. SiC powders for polishing are prepared as a first source material (17). A first SiC crystal (11) is grown by sublimating the first source material (17) through heating and precipitating an SiC crystal. A second source material (12) is formed by crushing the first SiC crystal (11). A second SiC crystal (14) is grown by sublimating the second source material (12) through heating and precipitating an SiC crystal. Thus, an SiC crystal and a method of manufacturing an SiC crystal capable of achieving suppressed lowering in quality can be obtained.

Bulk acoustic wave resonator structures include a bulk layer with inclined c-axis hexagonal crystal structure piezoelectric material supported by a substrate. The bulk layer may be prepared without first depositing a seed layer on the substrate. The bulk material layer has a c-axis tilt of about 32 degrees or greater. The bulk material layer may exhibit a ratio of shear coupling to longitudinal coupling of 1.25 or greater during excitation. A method for preparing a crystalline bulk layer having a c-axis tilt includes depositing a bulk material layer directly onto a substrate at an off-normal incidence. The deposition conditions may include a pressure of less than 5 mTorr and a deposition angle of about 35 degrees to about 85 degrees.