Relationship between metallic phase duration and transition boundary from metallic to gaseous phase in Ag break ARC

1994 ◽  
Vol 77 (9) ◽  
pp. 48-55 ◽  
Author(s):  
Kiyoshi Yoshida ◽  
Atsuo Takahashi
Keyword(s):  
Gaseous Phase ◽  
Metallic Phase ◽  
Phase Duration ◽  
Transition Boundary

Influence of Contact Materials on Phenomena in a Short Electrical Arc

2012 ◽  
Vol 510-511 ◽  
pp. 321-329 ◽  
Author(s):  
S.N. Kharin ◽  
M. Sarsengeldin
Keyword(s):  
Mathematical Model ◽  
Gaseous Phase ◽  
Thermionic Emission ◽  
Metallic Phase ◽  
Arc Length ◽  
Material Transfer ◽  
Contact Materials ◽  
Contact Erosion ◽  
Flux Evaporation ◽  
Gas Ionization

Investigation of transition phenomena accompanying the evolution of metallic phase of electric arc into gaseous phase is very important for the further progress in such fields as plasma technologies, electrical apparatus, plasmatrons and other technical applications. Some aspects of this transition are considered in presented paper on the base of mathematical model described dynamics of phenomena in the arc column, near-electrode zones, anode and cathode solids. Cathode and anode phenomena such as ion bombardment, thermionic emission, inverse electron flux, evaporation, radiation, heat conduction etc. are considered in dependence on time, current, opening velocity, parameters of the gas and contact materials. The conditions of the arc transition from one phase to another are formulated in terms of above characteristics and increasing of gas ionization level. Special experiments with two contacts materials, and have been carried to verify the mathematical model. The results of calculation and experimental data enables us to conclude that in metallic arc phase (short arc length), which is characterized by material transfer from the anode to the cathode, the erosion of contacts is considerably small than erosion of contacts both for resistive and inductive circuits, while in gaseous arc phase (long arc length) with opposite material transfer the rate of erosion depends on the inductance. If the inductance, then contacts have smaller erosion in comparison with contacts, however for inductive circuits situation is quite different, thus use of contacts in the case of long arcs burning in gaseous phase is more preferable. It was found also that the addition of niobium diselenide (1%) and tantalum (5%) into silver contact material which are sublimating into arc plasma enables to change ionization potential, that leads to decreasing of the arc temperature, arc duration and contact erosion.

Dynamic studies of silicide-mediated crystallization of amorphous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1352-1353
Author(s):  
C. Hayzelden ◽  
J. L. Batstone
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Metallic Phase ◽  
Single Crystal Substrate ◽  
Free Electrons ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Crystal Substrate ◽  
High Resolution Tem

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.

Metallic phase stabilization and phase diagram of (ET)3(HSO4)2

1991 ◽  
Vol 1 (10) ◽  
pp. 1365-1370 ◽  
Author(s):  
N. D. Kush ◽  
V. N. Laukhin ◽  
A. I. Schegolev ◽  
E. B. Yagubskii ◽  
E. Yu. Alikberova ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Metallic Phase ◽  
Phase Stabilization

DEGREE OF VALENCE MIXING IN THE METALLIC PHASE OF SmS AND IN TmSe

1976 ◽  
Vol 37 (C4) ◽  
pp. C4-267-C4-270 ◽  
Author(s):  
B. BATLOGG ◽  
A. SCHLEGEL ◽  
P. WACHTER
Keyword(s):  
Metallic Phase ◽  
Valence Mixing
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