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Volume 6 Issue 10
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Original Articles
NUCLEAR POLARIZATION OF 8Li PRODUCED BY BEAM-FOIL INTERACTION
WANG Zhenjie, WANG Cheng, GU Jiahui, GONG Ming
Chin. Phys. Lett. 1989, 6 (10): 433-435 .  
Abstract   PDF(pc) (41KB) ( 290 )
The nuclear polarization of 8Li produced by beam-foil interaction with a single carbon foil was measured. The sign of the polarization was also determined, and it tuned out to be opposite to that of the atomic polarization predicted by electric density gradient model.
ATOMIC-LIKE ORBITS AND LANTHNIDE CONTRACTION
LI Yongping, XIA Shangda, ZHANG Haifeng
Chin. Phys. Lett. 1989, 6 (10): 436-439 .  
Abstract   PDF(pc) (55KB) ( 413 )
The high order momentums of radial wavefunctions for 4f-series were calculated using atomic-like Gaussian basis. The lanthnide contraction and some comparisons were concluded.
XENON FLASH LAMP PUMPED SELF-FREQUENCY DOUBLING NYAB PULSED LASER
LUO Zundu, JIANG Aidong, HUANG Yichuan, QIU Minwang
Chin. Phys. Lett. 1989, 6 (10): 440-443 .  
Abstract   PDF(pc) (55KB) ( 646 )
Neodymium doped yttrium aluminum borate (NYAB) crystals with sizes up to 45mm have been grown successfully. NYAB rod of Ф4x 12 mm was pumped by xenon flash lamp, and several d of 0.53μm green laser output was obtained. The oscillation threshold, the pulse duration, the laser beam polarization, and the laser beam divergence were measured to be 78mJ, 100ns, 90% and 2mrad, respectively.
THE EFFECTS OF WEAK SELF-FIELDS ON ELECTRON ORBITS FOR A FREE ELECTRON LASER
LIU Shenggang, YU Junsheng, HUANG Lin*
Chin. Phys. Lett. 1989, 6 (10): 444-447 .  
Abstract   PDF(pc) (52KB) ( 344 )
A set of coupled equations for electron motion and the dispersion relation of electromagnetic wave (wiggler) in electron beam are studied. The instability of steady-state electron orbits is reduced to the problem of the fourth-order and fifth-order linear ordinary differential equations. It is found that the presence of self-fields plays an important role in determining the behaviour of stable electron orbits.
MOLECULAR DYNAMICS CALCULATION OF MOLTEN LiF, KC1 AND LiF-KCI(1:l) SYSTEM
SHAO Jun, SHU Guangyu, XU Hua*, CHEN Nianyi*
Chin. Phys. Lett. 1989, 6 (10): 448-450 .  
Abstract   PDF(pc) (44KB) ( 692 )
The partial RDF, the partial molar energy of mixing and the diffusion coefficient of Li+, K+, F- and Cl- of LiF-KCl(1:l) system have been calculated by computerized simulation of molecular dynamics method. The results are in agreement with the experimental values. The regularities about the local structure are discussed based on the results of calculation.
REGROWTH OF MBE-GaAs FILMS ON Si SUBSTRATES BY HIGH ENERGY ION-IMPLANTATION AND SUBSEQUENT ANNEALING
XIAO Guangming, YIN Shiduan, ZHANG Jingping, FAN Tiwen, LIU Jiarui*, DING Aiju*, ZHOU Junming*, ZHU Peiruan*
Chin. Phys. Lett. 1989, 6 (10): 451-454 .  
Abstract   PDF(pc) (63KB) ( 676 )
4.2MeV 7Li channeling technique, laser Raman scattering spectrometry, and TEM have been utilized to study the regrowth of MBE-GaAs films of ~μm thick on Si substrates by Si+ implantation (0.6-2.6Me V) and subsequent rapid thermal annealing. The results showed that crystalline disorder was greatly reduced in the recrystalized layers especially at the interface.

EFFECTS OF OH- IONS ON THE FORMATION AND THERMAL DECAY PROPERTIES OF F-AGGREGATE CENTERS IN LIGHTLY DOPED LiF: OH-
WU Zhenglong, YANG Bairui
Chin. Phys. Lett. 1989, 6 (10): 455-457 .  
Abstract   PDF(pc) (41KB) ( 344 )
Under identical irradiation conditios, higher concentrations of F+2, F-2, and F2 centers in lightly doped LiF: OH- than in pure LiF are found, but thermal stability of F+2 center in these two samples is almost the same. Products of OH- decomposition play an important roles in the formation and thermal decay processes of these F-aggregate centers.

NOVEL SEMICONDUCTOR SUBSTRATE FO-D BY HYDROGEN ION IMPLANTATION INTO SILICON
LI Jianming
Chin. Phys. Lett. 1989, 6 (10): 458-460 .  
Abstract   PDF(pc) (36KB) ( 584 )
A high resistivity layer formed beneath the silicon surface by using protons implantation and two-step annealing is described. Experiment shows that the surface Hall mobility of top layer has increased by 26%. This novel substrate challenges to GaAs (advantages of speed) and opens a new road for the realization of very high speed integrated circuits.
THE GENERATION OF BULK ACOUSTIC WAVES BY INTERDIGITAL TRANSDTJCEB
YIN Jianhua, SHUl Yongan, JIANG Wenhua
Chin. Phys. Lett. 1989, 6 (10): 461-464 .  
Abstract   PDF(pc) (74KB) ( 358 )
A simple method has been presented to analyse the generation of bulk acoustic waves (BAWs) by interdigital transducers (IDTs) on piezoelectric substrate. From calculation results with this method, we have found the strongest BAWs generation on Y-130°cut X-90°propagating LiNbO3. Some theoretical and experimental results for LiNbO3 with different orientations have been given.
TRANSFORMATION FROM ICOSAHEDRAL PHASE TO BODY CENTER CUBIC PHASE IN CUT DESCRIPTION
LI Fanghua*, PAN Guangzhao CHENG Yifan
Chin. Phys. Lett. 1989, 6 (10): 465-468 .  
Abstract   PDF(pc) (57KB) ( 383 )
The geometrical relation between quasiperiodic and periodic lattices is derived in both real and reciprocal spaces by means of the cut description. The relation between icosahedral phase and the corresponding body center cubic phase is discussed in detail.
X-RAY DIFFRACTION OF Cu/Ti FIBONACCI SUPERLATTICES
Zhu Ming, HU An, JIANG Shusheng, QUI Yan, FENG Lhan
Chin. Phys. Lett. 1989, 6 (10): 469-472 .  
Abstract   PDF(pc) (51KB) ( 399 )
1-D quasiperiodic (Fibonacci) Cu/Ti metallic superlattices have been prepared in a dual magnetron sputter deposition system. X-ray scattering measurements of these samples are presented. The X-ray diffraction peaks at low angles can be indexed by the projection method from the high-dimensional periodic structure. In the high angle region, there is one broad peak, which indicates that the samples are amorphous.
HIGH Tc SUPERCONDUCTIVITY ENHANCED BY ANTIFERROMAGNETISM
LIU Fusui
Chin. Phys. Lett. 1989, 6 (10): 473-476 .  
Abstract   PDF(pc) (47KB) ( 398 )
Using the Tc formula derived in this paper, the known experimental data and the known first principle calculations, we propose that the enhancement of phonon mediated superconductivity by antiferromagnetically coupled atoms causes the high Tc. Some predictions and discussions are given.
SUPERCONDUCTIVITY OF (TI1-xAlx) 2Ba2 Ca2Cu3Oy
WEI Chongde, LIN Qin, FENG Qingrong, SHEN Zhaohui, SUN Yunxi, LI Guozhong, WU Me, XUE Lixin, GAN Zizhao
Chin. Phys. Lett. 1989, 6 (10): 477-480 .  
Abstract   PDF(pc) (57KB) ( 323 )
The structure, magnetic, and superconducting properties of the (TI1-xAlx) 2Ba2 Ca2Cu3Oy with x=0.05, 0.1, 0.15, 0.2 were studied. The Tc R=0 depends on whether the sample has a 2223 phase structure or has a 2212 phase structure. The magnetic properties in low field were measured and discussed.
13 articles