http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
New Functional Hybrid Device Based on Semiconductor/Ferromagnet Nano Particle
장준연,Jooyoung Suh,김은규 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3
We report here an InAs 2DEG/Co hybrid device, including a micron-scaled InAs 2DEG micro-Hall bar and a single micro-structured Co ferromagnetic (FM) component. A clear hysteresis loop was found in the output signal for a micron-scaled Hall bar with a FM component due to the magnetic stray field emanating from the edge of the FM component. Switching was observed in the magnetic stray field and the output Hall voltage. We show that a magnetic stray field emanates from a single micro-structured FM component and that for micron-scaled devices, the stray field emanating from the FM particle increases with decreasing temperature. We report here an InAs 2DEG/Co hybrid device, including a micron-scaled InAs 2DEG micro-Hall bar and a single micro-structured Co ferromagnetic (FM) component. A clear hysteresis loop was found in the output signal for a micron-scaled Hall bar with a FM component due to the magnetic stray field emanating from the edge of the FM component. Switching was observed in the magnetic stray field and the output Hall voltage. We show that a magnetic stray field emanates from a single micro-structured FM component and that for micron-scaled devices, the stray field emanating from the FM particle increases with decreasing temperature.
張晙然,尹鐘瑞 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.12
The study aims at investigating the evolution of texture structure of rectangular-shaped pure aluminum processed by cyclic equal channel angular pressing. Strong recrystallization texture consisting of cube and rotated goss components is found in an unpressed sample. {001} <011> and {110} <211> textures are obviously dominant after one ECA pressing. Typical shear texture ({111}<110> and {111}<112>) gradually increases up to two pressings but decreases for further pressing. The goss and rotated goss textures are well developed while no specific shear texture appears after four times pressing. Repetitive ECA pressings result in relatively random oriented structure compared to that of extrusion or rolling process, which is probably due to the easy rotation of fine grains to the stable orientation.
반복 구속전단가공(ECAP)중 소둔한 순알루미늄의 조직과 인장특성
張畯然 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.12
The study focuses on understanding the effect of intermediate annealing on the tensile properties and microstructure of pure Al subjected to cyclic equal channel angular pressing(ECAP). Repetitive ECAP was performed up to 16 times at maximum. As-pressed samples were annealed at 200℃ for 1 hour after 2 and 4 passages. Some annealed samples were pressed further to compare the change in the properties of pure Al with the equivalent strain induced by ECAP but different thermal history. Annealing between the repetitive ECA pressing appears to be an effective method to form an equiaxed-fine-grained structure with high misorientation angles. It decreases the aspect ratio of micrograins while keeping the grain size unchanged. Further pressing after annealing results in an increase in the aspect ratio but small decrease in the grain size. It is speculated that recrystallization of ECA pressed Al is responsible for a significant increase in the misorientation angle.
Al-10%Si-2%Cu-1%Mg-0.5%Mn 합금 주괴의 고온변형
張畯然,文仁淇 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.8
Hot compression test was performed on Al-10%Si-2%Cu-1%Mg-0.5%Mn ingot in the temperature range 440∼500℃ and in the strain rate range 0.1∼10/sec in order to understand the hot deformation features and to explore the possibility of uniform distribution of eutectic Si particles. A typical stress-strain curve was well established where the stress increases sharply in the beginning of the deformation, and then decreases gradually in the strain rate of 0.5∼10/sec. Apparent activation energy of 65 ㎉/㏖ and stress exponent of 8.4 were evaluated from the peak stress. Deformation at low strain rate and high temperature is favorable in view of low flow stress and relatively uniform distribution of Si particles. Hard Si eutectics between primary Al grains begin to deform after soft Al grains are easily elongated in an early stage of the deformation. This type of deformation mode strongly demands at least 0.7 true strain to break the net-work structure of eutectic Si effectively. It is suggested that suitable heat treatment prior to the hot deformation be employed to ensure uniform distribution of fine Si particles.