Abstract: An apparatus for identifying metal corrosion includes a metal test piece, a push button timer, a liquid tank, a support, two fixed pulleys, a traction cable, a weight and a vibration motor. The support and the first pulley are in a lower portion of the tank. The second pulley is above the first pulley. The test piece is fixed on the support and connected to a first end of the traction cable which sequentially winds around the pulleys with a second end outside the tank. The weight, on which the motor is fixed, is suspended at the second end. The timer is under the motor. A corrosion solution is added into the tank, and the vibration motor provides alternating stress. When the metal test piece is broken, the weight and the motor are dropped and pressed on the electronic timer to record breaking time of the metal test piece.

Abstract: An apparatus for identifying metal corrosion includes a metal test piece, a push button timer, a liquid tank, a support, two fixed pulleys, a traction cable, a weight and a vibration motor. The support and the first pulley are in a lower portion of the tank. The second pulley is above the first pulley. The test piece is fixed on the support and connected to a first end of the traction cable which sequentially winds around the pulleys with a second end outside the tank. The weight, on which the motor is fixed, is suspended at the second end. The timer is under the motor. A corrosion solution is added into the tank, and the vibration motor provides alternating stress. When the metal test piece is broken, the weight and the motor are dropped and pressed on the electronic timer to record breaking time of the metal test piece.

Abstract: A semi-insulating silicon carbide monocrystal and a method of growing the same are disclosed. The semi-insulating silicon carbide monocrystal comprises intrinsic impurities, deep energy level dopants and intrinsic point defects. The intrinsic impurities are introduced unintentionally during manufacture of the silicon carbide monocrystal, and the deep energy level dopants and the intrinsic point defects are doped or introduced intentionally to compensate for the intrinsic impurities. The intrinsic impurities include shallow energy level donor impurities and shallow energy level acceptor impurities. A sum of a concentration of the deep energy level dopants and a concentration of the intrinsic point defects is greater than a difference between a concentration of the shallow energy level donor impurities and a concentration of the shallow energy level acceptor impurities, and the concentration of the intrinsic point defects is less than the concentration of the deep energy level dopants.

Abstract: A technology for growing silicon carbide single crystals by PVT (Physical Vapor Transport) and a technology for in-situ annealing the crystals after growth is finished is provided. The technology can achieve real-time dynamic control of the temperature distribution of growth chamber by regulating the position of the insulation layer on the upper part of the graphite crucible, thus controlling the temperature distribution of growth chamber in real-time during the growth process according to the needs of the technology, which helps to significantly improve the crystal quality and production yield.

Abstract: A semi-insulating silicon carbide monocrystal and a method of growing the same are disclosed. The semi-insulating silicon carbide monocrystal comprises intrinsic impurities, deep energy level dopants and intrinsic point defects. The intrinsic impurities are introduced unintentionally during manufacture of the silicon carbide monocrystal, and the deep energy level dopants and the intrinsic point defects are doped or introduced intentionally to compensate for the intrinsic impurities. The intrinsic impurities include shallow energy level donor impurities and shallow energy level acceptor impurities. A sum of a concentration of the deep energy level dopants and a concentration of the intrinsic point defects is greater than a difference between a concentration of the shallow energy level donor impurities and a concentration of the shallow energy level acceptor impurities, and the concentration of the intrinsic point defects is less than the concentration of the deep energy level dopants.

Abstract: A technology for growing silicon carbide single crystals by PVT (Physical Vapor Transport) and a technology for in-situ annealing the crystals after growth is finished is provided. The technology can achieve real-time dynamic control of the temperature distribution of growth chamber by regulating the position of the insulation layer on the upper part of the graphite crucible, thus controlling the temperature distribution of growth chamber in real-time during the growth process according to the needs of the technology, which helps to significantly improve the crystal quality and production yield.