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101.
The Si doped (Cu0.5Tl0.5)Ba2Ca2Cu3−ySiyO10−δ (y=0, 0.25, 0.5, 0.75, 1.0, 1.25) superconductor samples have been synthesized to investigate the effect of mobile carriers on the critical temperature and magnitude of diamagnetism of this family of cuprates. The Si doped samples have tetragonal structure as observed from the X-ray diffraction spectra. The c-axis length of the unit cell of (Cu0.5Tl0.5)Ba2Ca2Cu3−ySiyO10−δ was increased after the increase of Si concentration, whereas the critical temperature and the magnitude of diamagnetism have been decreased. The decrease in Tc(0) and magnitude of diamagnetism is possibly due to the deficiency of carriers in CuO2/SiO2 planes caused by the +4 state of Si atoms. However, the post-annealing of these samples in oxygen atmosphere has increased the critical temperature and the magnitude of diamagnetism. The FTIR absorption measurements of (Cu0.5Tl0.5)Ba2Ca2Cu3−ySiyO10−δ samples have shown a softening of the apical oxygen mode of the type Cu(1)OACu(2) and TlOACu(2) with increased concentration of Si in the unit cell; the softening of this mode is directly linked with the increase in the c-axis lattice parameter of the (Cu0.5Tl0.5)Ba2Ca2Cu3−ySiyO10−δ superconductor. 相似文献
102.
Yung Cha Lihua Chen Thomas Askew Boyd Veal John Hull 《Journal of magnetism and magnetic materials》2007
An innovative method of manipulating magnetic carriers is proposed, and its feasibility for drug delivery and therapy is demonstrated experimentally. The proposed method employs pulsed-field solenoid coils with high-critical- temperature (Tc) superconductor inserts. Pulsed current is used to magnetize and de-magnetize the superconductor insert. The proposed method was demonstrated to be able to (1) move magnetic particles, ranging in size from a few millimeters to 10 μm, with strong enough forces over a substantial distance, (2) hold the particles at a designated position as long as needed, and (3) reverse the processes and retrieve the particles. We further demonstrated that magnetic particles can be manipulated in a stationary environment, in water flow, and in simulated blood (water/glycerol mixture) flow. 相似文献
103.
本文采用测量样品与磁场的机械力作用来观测迈斯纳效应 ,并通过扫描线的变化量ΔL与温度T变化曲线得到超导体的转变温度TC 值 相似文献
104.
K. Kajikawa K. Funaki K. Shikimachi N. Hirano S. Nagaya 《Physica C: Superconductivity and its Applications》2010,470(20):1321-1324
AC losses in a superconductor strip are numerically evaluated by means of a finite element method formulated with a current vector potential. The expressions of AC losses in an infinite slab that corresponds to a simple model of infinitely stacked strips are also derived theoretically. It is assumed that the voltage-current characteristics of the superconductors are represented by Bean’s critical state model. The typical operation pattern of a Superconducting Magnetic Energy Storage (SMES) coil with direct and alternating transport currents in an external AC magnetic field is taken into account as the electromagnetic environment for both the single strip and the infinite slab. By using the obtained results of AC losses, the influences of the transport currents on the total losses are discussed quantitatively. 相似文献
105.
Goos-H?nchen(GH)位移是一种特殊的光学现象,具有广泛的应用.构造材料光学性质的差异对同一结构的GH位移有很大影响.在近零介电常数区,本文比较研究了不同偏振态的光波入射到超导薄层上的GH位移.当以大于临界角的入射角入射时,s偏振光的GH位移始终保持为正值,而p偏振光的GH位移的正负与超导材料的介电常数为零时的波长相关联.当入射光波长大于该波长时,GH位移会出现负值.相关参数对不同偏振态下的GH位移的影响存在较大差异.相对于p偏振光,GH位移在s偏振光入射时随相关参数的变化规律较为简单.超导材料在光子学领域具有广泛的应用,计算结果为基于超导材料的新型光子学器件研究开发提供了参考. 相似文献
106.
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108.
A surface resistance as small as RS=3×10–2 Ohms has been computed at T=8 K, for v=0.6 Thz (v=20 cm–1), for an YBaCuO film deposited on an MgO substrate. The calculations are made with the refractive index computed from the Far IR transmission spectra of a 400 Å thick film.Still lower values are obtained with another sample, 300 Å thick of exceptional quality (RS=1.2×10–2 Ohms). 相似文献
109.
110.
Abstract We made the superconductor of Bi2Sr2CaCu2Oγ by the solid state reaction. According to the results of measurement by infrared spectrophotometer with the varying of wave number from 4000 to 400 cm?1. We discovered three infrared absorption peaks at room temperature, i.e., peak A1 at 500–550 cm?1, peak A2 at 800–840 cm?1 and peak A3 at 1370–1420 cm?1. We find that peak A1 is due to impure phase, peak A2 is related with the crystal structure and peak A3 is caused by the vibration of the atom layers of calcium. 相似文献