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  • 1
    Electronic Resource
    Electronic Resource
    Annealing studies of low-temperature-grown GaAs:Be (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 1699-1707 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The isochronal and isothermal annealing characteristics of acceptor-doped GaAs:Be grown at low substrate temperatures (300 °C) by molecular-beam epitaxy (LTMBE) have been studied. The Be was introduced in a range of concentrations from 1016 to 1019 cm−3. Electrical measurements of as-grown material up to the highest Be concentration of 1019 cm−3 show that no free holes are contributed to the valence band even though Raman spectroscopy of the Be local vibrational mode indicates that the majority of the Be impurities occupy substitutional sites. It is proposed that Be acceptors are rendered inactive by the high concentration of AsGa-related native donor defects present in LTMBE material. The concentration of AsGa-related defects in the neutral charge state was estimated from infrared absorption measurements to be as high as 3×1019 cm−3. A distinct annealing stage at 500 °C, similar to that found in irradiation-damaged and plastically deformed GaAs, marks a rapid decrease in the concentration of AsGa-related defects. A second annealing stage near 800 °C corresponds to the activation of Be acceptors. The presence of gallium vacancies VGa was investigated by slow positron annihilation. Results indicate an excess concentration of VGa in LTMBE layers over bulk-grown crystals. Analysis of isothermal annealing kinetics for the removal of AsGa-related defects gives an activation energy of 1.7±0.3 eV. The defect removal mechanism is modeled with VGa-assisted diffusion of AsGa to As precipitates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351200
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  • 2
    Electronic Resource
    Electronic Resource
    Absolute pressure dependence of the second ionization level of EL2 in GaAs (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 1143-1145 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of deep level transient spectroscopy experiments with the second ionization level of the double donor defect (EL2) under uniaxial stress in p-type GaAs. We measure the shift in the hole emission rate as a function of stress applied in the [100] and [110] directions. By modeling the valence band with two independently displacing bands and appropriately derived effective masses, we determine the absolute hydrostatic pressure derivative of the defect to be 39±15 meV GPa−1. The shear contribution is negligible. These results are very different from those obtained for the first ionization level, which has a much higher absolute pressure derivative of 90 meV GPa−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102544
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  • 3
    Electronic Resource
    Electronic Resource
    Room temperature discharge characteristics of Li/NH4NO3−LiNO3-amide cells using silver salts as active cathode materials (1986)
    Springer
    Journal of applied electrochemistry 16 (1986), S. 920-928 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The discharge characteristics of cells using lithium anodes in conjunction with nitrate-amide melt electrolytes and silver salt cathodes are presented. The use of insoluble or sparingly soluble silver salts as active cathode materials for ambient temperature galvanic cell cathodes can allow higher rate discharges than otherwise possible using melt reduction as the cathode reaction. The cathode materials studied were: Ag2CrO4, Ag2MoO4, Ag2WO4, Ag2PO4, Ag2SO4, AgIO3, AgIO4, AgF, AgCl, AgBr, AgI, Ag4RbI5 and Ag2O. The reduction characteristics of silver ions added to natrate-amide melts are also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01006539
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  • 4
    Electronic Resource
    Electronic Resource
    The electrochemistry of nitrate-amide melts: Reactions of nickel and copper in nitrate-amide melts (1986)
    Springer
    Journal of applied electrochemistry 16 (1986), S. 229-238 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Copper and nickel may be electrodeposited from their ions in solution in nitrate-amide melts at room temperature. In the ammonium nitrate-acetamide-urea melt at 23°C, the reduction to the metal competes with the corrosion reaction at low rates and with the reduction of the ammonium and nitrate ions of the melt at high current densities. Two distinct types of nickel complexes are found in solution. The nickel complex formed by the corrosion reaction is bound by at least one ammonia ligand. Nickel complexes formed by dissolving the halide in the melt show evidence of coordination by less strongly bounding ligands, probably by amides. Similarly, the visible spectra of copper chloride in solution suggest that the cupric ions are coordinated primarily by amides. The copper corrosion reaction produces a complex with a spectra distinctly different from that of cupric chloride in solution. The shift in absorption maxima suggests that the copper complex formed by the corrosion reaction has at least one ammonia ligand in the coordination sphere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01093355
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  • 5
    Electronic Resource
    Electronic Resource
    The electrochemistry of nitrate-amide melts: Reactions of the calcium anode in room temperature nitrate-amide melts (1986)
    Springer
    Journal of applied electrochemistry 16 (1986), S. 101-108 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The discharge characteristics of calcium anodes in room temperature nitrate-amide melts are strongly dependent on the acidity of the melt. A significant increase in the potentiostatic discharge current is noted on acidification of LiNO3-acetamide-urea melts with the strong acid NH4NO3. Acidic species act to break down the passivating film on the anode. No significant depassivation is noted on addition of halides. Galvanostatic discharges at varying current densities and different melt compositions show the effects of a passivating film on the observed anode potential. Discharges of galvanic cells based on the calcium anode in nitrate-amide melt electrolytes have been demonstrated at current densities above 1 mA cm−2 using a AgCl cathode.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01015989
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  • 6
    Electronic Resource
    Electronic Resource
    Laser dye stability, part 12. The pyridinium salts (1987)
    Springer
    Applied physics 43 (1987), S. 155-160 
    Details
    ISSN: 1432-0649
    Keywords: 78.60 ; 61.8 ; 82.5
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The fluorescence and lasing characteristics of 25 oxazole dyes have been investigated. Lasing was attempted using flashlamp pumping with and without the presence of oxygen. A few of the dyes showed the highest laser lifetimes covering the wavelength region of 495–523 nm that we have ever tested. Other dyes showed high laser outputs. Many of the dyes had useful flashlamp-pumped laser characteristics using water as the solvent. Although the best lasing conditions were observed in the absence of oxygen, good lifetimes could be obtained under air for solvents such as ethanol/water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695616
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  • 7
    Electronic Resource
    Electronic Resource
    Laser dye stability, part 11. The fluorinated azacoumarin dyes (1987)
    Springer
    Applied physics 42 (1987), S. 79-83 
    Details
    ISSN: 1432-0649
    Keywords: 78.60 ; 61.8 ; 82.5
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The lasing outputs and lifetime constants are reported for the fluorinated azacoumarin dyes, AC2F, AC3F, and AC4F, in a variety of solvents. Most of the tests were made under both air and argon. The best results were obtained using solvents such as ethanol mixed with water or ethylene glycol under air. The dyes AC2F or AC4F gave results that were comparable or superior to those of AC3F. These dyes represent the longest lived of the presently known coumarin laser dyes when used with a solvent capable of hydrogen bonding.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694814
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  • 8
    Electronic Resource
    Electronic Resource
    Search for efficient, near UV lasing dyes. III. Monocyclic and miscellaneous dyes (1976)
    Springer
    Applied physics 9 (1976), S. 67-70 
    Details
    ISSN: 1432-0630
    Keywords: Lasing dyes ; Ultra-violet ; Monocyclic dyes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A potential new class of “monocyclic” lasing dyes is discussed and four families out of nine within the class are examined. The 2,6-diaminopyridines in acid are found to lase under flashlamp excitation but show low slope efficiencies and lower stabilities than the “bicyclic” dyes described previously. Other, miscellaneous dyes show oxygen quenching of laser action rather than enhancement and the best of these produces short pulses under long pulse excitation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00901911
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