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Volume 4 Issue 12
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Original Articles
STUDY OF Ba-Y-Cu-O THIN FILMS WITH ZERO RESISTANCE AT LN2 REGION PREPARED BY MAGNETRON SPUTTERING
ZHAO Bairu, WANG Huisheng, LU Yong, SHI Yinhuan, LI Lin, YUAN Caiwen, ZHAO Yuying, GAO Ju.
Chin. Phys. Lett. 1987, 4 (12): 529-532 .  
Abstract   PDF(pc) (51KB) ( 384 )
We briefly describe our results to date on the magnetron sputtering deposition of BaxY1+xCuO3-y thin films with Tc onset=96K and TR=0=83K. We emphasize the importance of the characteristics of the substrate material. The perovskite-SrTiO3 substrate ddposits high TR=0 and Jc films. X-ray diffraction studies show that they are of single phase orthorhombic perovskite structure.
ENHANCEMENT OF NEUTRON DIFFRACTION INTENSITIES FROM KTP SINGLE CRYSTALS WITH THE APPLICATION OF A DC FIELD
YANG Zhen
Chin. Phys. Lett. 1987, 4 (12): 533-536 .  
Abstract   PDF(pc) (38KB) ( 395 )
The anisotropic enhancement of neutron diffraction intensities from KTP single crystals with the application of an external DC voltage along its c-axis were investigated, and the similarity of this effect to that observed in α-LiIO3 crystals is discussed.
A LOCALIZED VIBRATION MODE RELATED TO THE SUPERCONDUCTING PHASE IN Y-BA-CU-O SYSTEM
CHEN Jianmin, CAI Peixin, ZHAO Yonggang, QI Mingwei, BAI Guoren, XIE Leiming
Chin. Phys. Lett. 1987, 4 (12): 537-540 .  
Abstract   PDF(pc) (45KB) ( 421 )
The IR absorption spectra of superconducting and nonsuperconducting samples have been investigated. An IR absorption peak at about 447cm-1 was found. It might be caused by Cu-O localized vibration mode in the superconducting sample. A possible vibration model was proposed.
NEUTRON-IRRADIATION EFFECTS ON CRYSTALLIZATION OF Cu-Ti GLASSES
DONG Yuanda, WU Guoan*, CHENG Lifang, XIAO Keqin, LI Xiaoguang, ZHU Zhaoqin, HE Yizhen
Chin. Phys. Lett. 1987, 4 (12): 541-544 .  
Abstract   PDF(pc) (50KB) ( 418 )
The effect of neutron-irradiation on crystallization of Cu-Ti glasses of four compositions was systematically studied by differential scanning calorimetry (DSC) and internal friction measurements. The results show that the susceptibility of the glasses to irradiation is quite composition dependent.
ELECTRONIC STRUCTURE OF QUASI-PERIODIC METALLIC SUPERLATTICES
PANG Gendi, YUAN Jian, Chien-Hua Tsai*
Chin. Phys. Lett. 1987, 4 (12): 545-548 .  
Abstract   PDF(pc) (37KB) ( 356 )
The electronic structure of quasi-periodic metallic superlattices has been studied under the tight-binding approximation. The electronic densities of states are displayed for typical examples as results of numerical evalution.
EXPERIMENTAL EVIDENCE OF FLUX JUMPS IN Y-Ba-Cu-O SUPERCONDUCTORS
XIA Guoqiang, MA Hong, YAN Shousheng
Chin. Phys. Lett. 1987, 4 (12): 549-552 .  
Abstract   PDF(pc) (45KB) ( 403 )
The time dependence of the penetration of a weak ac field into Y-Ba-Cu-O superconductors at various dc fields, 0-1500G, was measured at liquid nitrogen temperature. It is found that the signals are very unstable at certain field regions for some of the samples. We believe that this is a direct evidence of the existence of flux jumps which are characteristic of granular superconductors.
RF-CAPACITIVE TRANSDUCER APPLIED TO GRAVITATIONAL WAVE DETECTOR
ZHU Ning, GUAN Tongren, HU Enke
Chin. Phys. Lett. 1987, 4 (12): 553-556 .  
Abstract   PDF(pc) (55KB) ( 390 )
We have designed and made an rf-capacitive transducer for the square antenna of our laboratory. A variable capacitor ( ~2000 PF), which is modulated by gravitational radiation, works in a 5 MHz resonant circuit. The most advantageous feature of this transducer is that the sensitivity is highly improved by introducing a π-net-work transformation in the resonant circuit. The sensitivity of 9.4MHz/M is obtained.
MEASUREMENT OF ULTRAFAST DEPHASING TIME OF RUBY BY TRANSIENT GRATING WITH INCOHERENT LIGHT
ZHANG Ruihua, JIANG Qian, YU Zuhe, FU Panming, YE Peixian
Chin. Phys. Lett. 1987, 4 (12): 557-560 .  
Abstract   PDF(pc) (57KB) ( 419 )
Dephasing time T2 of ruby in the absorption band 4T2 has been measured for the first time using the method of transient grating with incoherent light. The population grating was induced in the material by two broad-band nanosecond pulses of a dye laser and probed by a Continuous Wave (CW) Ar+ laser. A t room temperature, T2=0.04 ~0.08 ps was obtained when the sample was excited at λ=5640Å.
ENERGETIC PARTICLE STABILIZATION OF m = l INTERNAL KINK MODE IN TOKAMAKS
R. J . Hastie*, CHEN Yanping, KE Fujiu, CAI Shidong(S, T.Tsai), L . Chen**
Chin. Phys. Lett. 1987, 4 (12): 561-564 .  
Abstract   PDF(pc) (44KB) ( 496 )
The stability of m=l internal kink mode in a tokamak plasma with an anisotropic energetic particle component has been analyzed using the generalized energy principle. It is found that employing barely trapped energetic particles can significantly improve the stability properties.
ANNEALING DYNAMIC BEHAVIOR OF Rh ENERGY LEVELS IN n-Si SAMPLES
ZHOU Jie, JI Xiujiang, LI Shuying, LIN Xulun*
Chin. Phys. Lett. 1987, 4 (12): 565-568 .  
Abstract   PDF(pc) (44KB) ( 411 )
The results of annealing behavior of Rh energy levels in n-Si are presented. Two energy levels E(0.31) and E(0.58) are observed. According to the generation and growth rules of these levels and their equal concentration, it is supposed that the two levels are related to the atoms of Rh, and they belong to the same center, but their charged states are different.
@AMORPHOUS Ni50Ti50 FILM FORMED BY SOLID-STATE REACTION
YAN Zhihua, WANG Wenkui
Chin. Phys. Lett. 1987, 4 (12): 569-571 .  
Abstract   PDF(pc) (31KB) ( 493 )
The solid-state reaction technique has been used to form the amorphous Ni50Ti50 film. The alternative layers were prepared by an electron beam evaporating apparatus. The amorphization was determined by means of X-ray diffraction and confirmed by DSC experiments.
11 articles