高压物理学报

Effects of Recrystallized Graphite on the Nucleation of Diamond in Film Growth Reaction

WANG Guang-Zu, ZHENG Zhou, CHEN Lun

1989, 3(3): 177-180 . doi: 10.11858/gywlxb.1989.03.001

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Abstract:
On the basis of the experimental phenomena, it has been analyzed in this paper that the dispersion and dissolving processes of the carbon sources in the solvent-catalyst metal and the formation of the recrystallized graphite in the early period of the diamond synthesis. From the relationship between the crystal size and the solvability, the effects of the radius of recrystallized graphite on the nucleation and growth of diamond are also preliminarily discussed.

Phonon Generation and Energy Localization by Moving Screw Dislocations in Rapid Deformation

DONG Lian-Ke, WANG Ke-Gang

1989, 3(3): 181-186 . doi: 10.11858/gywlxb.1989.03.002

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Abstract:
From the viewpoint of quantum mechanics, the phonon field generated by a moving screw dislocation is examined. It is shown that phonon emission is in the neighborhood of active slip planes and phonon energy is locally concentrated in these planes where they form hot spots. Finally, the phonon energy spectrum is examined and found that it is non-Boltzmann.

Sound Velocities at High Pressures and Shock-Melting of Copper

HU Jin-Biao, JING Fu-Qian, CHENG Ju-Xin

1989, 3(3): 187-197 . doi: 10.11858/gywlxb.1989.03.003

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Abstract:
Sound velocities of copper at high shock pressures were determined by using optical analyzer technique under on-dimensional strain condition. The measured pressure range was from 125 GPa to 170 GPa. Combined with the data given earlier by Broberg, Morris et al., Altshuler et al., and ours, a comprehensive analysis for sound velocities at pressures of 0~170 GPa was also made. It shows the elastic sound velocity cl of solid-state copper, when the pressure is between 0~156 GPa, monotonically increases with the increasing of shock pressure and can be represented by the following equation ln cl=1.565 888-2.645 48810-2ln p+2.710 68110-2ln2p. Relations errors between the data deduced from the above equation and the measurement are less than 1.3%. Moreover, the shock-melting, marked as the sudden drop of sound velocity in c-p relation, occurs at 156~159 GPa and completes at about 170 GPa, for which a rather satisfactory verification is also acquired by the Lindeman melting-law in the analysis.

High-Pressure Synthesis and Luminescence Characters of Er3+-Activated Strontium Silicate

YANG Jing-Hai, WANG Yi-Feng, LIU Hong-Jian, SU Wen-Hui, LI Bin, OUYANG Chang-Jun, XING Zhi-Ming

1989, 3(3): 198-202 . doi: 10.11858/gywlxb.1989.03.004

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Abstract:
Sr2SiO4:Er3+Bi3+, SrSiO3:Er3+Bi3+ were synthesized by a high-pressure method for the first time. The effect of synthesizing pressure and temperatures on luminescence properties and structures of the samples was studied. The samples synthesized by both high-pressure and atmosphere method were analyzed with SEM. Compared with those synthesized under atmosphere, the red shift of emission peak for the sample obtained by high pressure occurred, the half-widths increased obviously and the intensity and quantum luminescence efficiency decreased. The structural transition of SrSiO3:Er3+Bi3+ occurred, while the changing of lattice parameters and the intensity reversion of the main diffraction peaks appeared without structural transition for the Sr2SiO4:Er3+Bi3+. It shows that the variation of luminescence characters is resulted from the pressure-induced changing of the crystal field, coulomb and spin-orbit interaction in the ligand.

Symmetrical and Unsymmetrical Frictions in Pyrophyllite Medium on High-Temperature Measurement in Piston-Cylinder Type High-Pressure Chamber

SHEN Zhong-Yi, YAO Yu-Shu, ZHANG Yun, WANG Song-Tao

1989, 3(3): 203-210 . doi: 10.11858/gywlxb.1989.03.005

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Abstract:
Frictions in pyrophyllite medium at elevated temperature in piston-cylinder type apparatus are examined by measuring the melting curve of lead. The obtained results show evident unsymmetrical frictions grown out during pressure calibration at higher temperatures. As a result, the widely used fixed points calibration method becomes inapplicable. As temperature differs greatly at the central and outside parts of the assembly, this unsymmetrical friction is assumed to be originated from the corresponding evident disparity in mechanical properties of the medium, showing a large differential loading. We conclude that as the pyrophyllite is very cheap and easy in machining, it should get wide application as a qualified medium in high-temperature high-pressure measurement of physical properties, if the unsymmetrical friction is understand in its nature and if it could be well controlled.

Experimental Studies on the Crystallization of Amorphous Fe40Ni40P12B8 Alloy under Shock Loading

HE Hong-Liang, JIN Xiao-Gang, CHEN Pan-Sen, WANG Wen-Kui

1989, 3(3): 211-220 . doi: 10.11858/gywlxb.1989.03.006

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Abstract:
The shock-induced crystallization of amorphous Fe40Ni40P12B8 alloy was investigated in this paper. The shock loading condition was produced by the impact of high velocity projectile, which had been accelerated by a two-stage light-gas gun to a definite velocity. The experimental results indicated as follows: (1) the crystallization of amorphous Fe40Ni40P12B8 alloy can be induced under the shock loading in about 10-6 s duration; (2) the threshold pressure of crystallization is 30~50 GPa, and the correspondent temperature is 510~800 K; and (3) the precipitated phases depends on the pressure applied, at lower pressure the phases are -(Fe, Ni) solid solution and Fe3P type Fe3(P0.37B0.63) compound, at higher pressure (higher than 60 GPa) the phases are -(Fe, Ni) solid solution and two Fe3P type of Fe3(P0.37B0.63), (Fe, Ni)3P compounds.

The Effects of the Type and Amount of the Grain Boundary Phase in s-Type Polycrystalline Diamond on Its Physical Properties

YU Hong-Chang, LI Shang-Jie

1989, 3(3): 221-225 . doi: 10.11858/gywlxb.1989.03.007

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Abstract:
There are mainly two types of sintered typed polycrystalline diamond with or without additives. This article concerns only the first type on and deals with the effect of the type and amount of the grain boundary phases on the relative wear resistance, strength and thermostability. We found both the amount of intermediate transiting phases formed in grain boundary phases and the thermostability are dependent upon the types of the grain boundary phases.

Studies on the Shock Adiabatics and Equation-of-State of Nandan Iron Meteorite

FU Shi-Qin, JIN Xiao-Gang, CHEN Pan-Sen

1989, 3(3): 226-233 . doi: 10.11858/gywlxb.1989.03.008

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Abstract:
The shock adiabatic of Nandan iron meteorite was measured by using impedance-match method and a two-stage light-gas gun as its loading tool. Pressure ranges are from 62 GPa to 208 GPa. The shock velocity D versus particle velocity u can be expressed as D=3.884+1.840u-0.12267u2 (km/s). With the assumptions of Born-Meyer potential suitable interatomic potential and the thermal contributions necessitating inclusions of non-harmonic vibration term and free-electron term, the equation-of-state of Nandan iron meteorite is also deduced in this paper.

A Semi-Empirical Equation for Estimating the Micro-Jet Ejection from Shocked Free-Surface

HAN Chang-Sheng

1989, 3(3): 234-240 . doi: 10.11858/gywlxb.1989.03.009

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Abstract:
Based on the classical steady-jet theory and the equivalent linear mass assumption proposed by the author, a semi-empirical analytic equation for estimating the micro-jet ejection mass quantity from shocked free-surface with artificial wedged-grooves is developed in this paper. Comparing with a few practical examples, including experimental and two-dimensional numerical simulations, it shows the semi-empirical equation is relatively good for utilization in rough estimation.

Influence of Pressure on the TlPbxBaCa3Cu3O Superconductors

LIU Zhen-Xing, LIN Ming-Zhu, TANG Ming-Hua, MENG Xian-Ren, LIN Zhen-Jin, SANG Li-Hua, TU Qing-Yun, HAN Wei, REN Yan-Ru

1989, 3(3): 241-245 . doi: 10.11858/gywlxb.1989.03.010

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Abstract:
Pb doped TlBaCaCuO compounds with nominal composition TlPbxBaCa3Cu3Oy have been synthesized and their physical properties have been studied. The pressure-dependence of Tc has also been studied. It is found that Tc increases with pressure at a rate of dTc0/dp=2.2 K/GPa for x=0.5, which is higher than dTc0/dp=1.8 K/GPa for pure TlBaCaCuO.

A New Calculation of Energy and Polarizability of Hydrogen-Like Atom under High Pressure

SUN Feng-Guo, LIN Hua-Ling

1989, 3(3): 246-249 . doi: 10.11858/gywlxb.1989.03.011

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Abstract:
The energy and polarizability of a model hydrogen-like atom limited in a spherical shell of radius r0 are calculated using new trial wave-function. The energy and polarizability are obtained as functions of the radius r0 and corresponding pressure p. In comparison with results in reference [1], ours are obviously better.

The Nucleation Character of Diamond in Two Kinds of Raising Pressure Program

ZHAO Jian-Zhong, YANG Zong-Qing, YU Hong-Chang, SU Wen-Hui

1989, 3(3): 250-255 . doi: 10.11858/gywlxb.1989.03.012

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Abstract:
In the temperature range between 1 573 to 1 663 K, the pressure inhibiting the nucleation of diamond of recrystallized graphite is about 0.4 GPa. This pressure is related to the formation time of the recrystallized graphite. X-ray diffraction analyses indicate that the d002 of recrystallized graphite decreases with the increase of the inhibition of nucleation.

1989 Vol. 3, No. 3

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