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  • 1
    Electronic Resource
    Electronic Resource
    Structure and luminescence of annealed nanoparticles of ZnS:Mn (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 4985-4993 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Structural and light-emitting properties of nanoparticles of ZnS:Mn annealed in vacuum at temperatures up to 525 °C are presented. Annealing the 3.5 nm particles at temperatures up to 350 °C caused growth of some particles without substantial change in the luminescence or ZnS lattice. After annealing at 400–525 °C, the high-temperature wurtzite phase of ZnS appeared, accompanied by an increase of the average particle diameter to approximately 100 nm and a rearrangement of the Mn ions. Dramatic increase in cathodoluminescence emission was also observed and is compared to the structural information obtained from electron microscopy, x-ray diffraction, x-ray absorption fine structure, and electron paramagnetic resonance measurements. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1314326
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Linear theory of a field-emitter-array distributed amplifier (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 7098-7110 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A small-signal theory of a field-emission-array distributed amplifier consisting of two microstriplike transmission lines is developed to calculate the premodulation in the input channel and the gain in the output channel. A first-order perturbation analysis is used to treat the beam-wave coupling in this device within the framework of a cold fluid model. The dependence of the linear gain on frequency, beam voltage, beam current, and the circuit parameters is derived to determine the parameter range for operation of the device. It is found that the height of the circuit is restricted to lie between 80 and 120 μm to maintain high electronic gain and low loss arising from the finite conductivity of the metal surfaces. In an output line having a substrate with a relative dielectric constant, εr=4, a net gain of 7 dB/cm is calculated with a beam voltage of 60 V and a beam current of 2.14 A/cm in each wedge of a seven-wedge emitter array. As the beam voltage is increased in the range 60–100 V, the net gain decreases from 7.0 to 3.0 dB/cm, while the frequency for maximum gain increases from 50 to 80 GHz with a corresponding increase in the bandwidth. The small-signal instantaneous bandwidth is in excess of 60%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.345060
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  • 3
    Electronic Resource
    Electronic Resource
    Analysis and design of microwave amplifiers employing field-emitter arrays (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 1485-1504 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An analysis of the microwave ( f(approximately-greater-than)1 GHz) properties of field-emitter arrays (FEAs) and several representative medium power (10–100 W) microwave amplifiers employing FEAs is presented. The FEA analysis is limited to parallel-plate structures having discrete pointlike vertical emitter tips and gate apertures aligned to each tip. A transmission line analysis of wave propagation in this structure is presented and used to evaluate the geometries and materials needed for microwave operation. This analysis is used to investigate the performance capabilities and emitter requirements of both modulated-emission linear beam tubes and microdevices based on FEAs. Specific microtriode designs are used to investigate practical problems such as space charge and thermal effects. Competitive performance should be achievable in gated-emission linear beam tubes by using FEAs that perform at levels previously reported by several laboratories. Existing FEA technology (currents of 10 μA per emitter, transconductances of 1 μS per emitter, 1 μm oxide thickness, and 3 μm emitter spacing) is suitable for use in cavity klystrodes(r) at frequencies through 10 GHz, and in moderately bunched beam (bunch width of 180°), octave-bandwidth traveling-wave-tube applications through 3 GHz. Extending the operating frequency and/or reducing the bunch width will require a larger ratio of transconductance to current. Microtriodes operating at 10 GHz will benefit from a modified FEA structure and improved emitter performance.An extra acceleration electrode must be added above the gate aperture to alleviate problems due to space charge between the gate and collector, and the gate oxide thickness must be increased to at least 2 μm. A FEA incorporating these features and capable of producing 5 μS and 100 μA per emitter could generate 130 W from a 5-mm-wide device with 8.6 dB gain, 7% bandwidth, and 36% power added efficiency. To allow higher gain and wideband operation, the transconductance at a given current must be increased. A FEA capable of producing 5 μS at only 10 μA per emitter would result in a microtriode with more than 1 octave bandwidth, 45 W output power, 10 dB gain, and 34% power added efficiency. Anode-to-case temperature differences of less than 100 °C appear possible in this device if BeO is used as the dielectric.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353223
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  • 4
    Electronic Resource
    Electronic Resource
    The Infrared and Ultraviolet Absorption Spectra of Two Isomers of Mesityl Oxide (1947)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 69 (1947), S. 1630-1631 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01199a018
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Ultrahigh-vacuum field emitter array wafer tester (1987)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 58 (1987), S. 301-304 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The device reported here allows the researcher the opportunity of gaining primitive yield information, threshold voltages, emission stability, and other information, e.g., gas effects, on field emitter arrays (FEA) which are microminiature "vacuum tubes'' fabricated by microelectronic processing methods on silicon wafers, without scribing, dicing, and mounting each device on individual vacuum-compatible headers. This device also speeds up the entire data-acquisition process by requiring only one ultrahigh-vacuum pumpdown and one set of vacuum feedthroughs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1139275
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    Mn-doped ZnS nanoparticles as efficient low-voltage cathodoluminescent phosphors (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 802-804 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have synthesized nanoparticles of ZnS doped with Mn for potential use as cathodoluminescent phosphors in field-emission displays (FEDs). We show that the cathodoluminescent efficiency of particles ≤100 nm in diameter is within 40% of that of a commercial (micron-sized) phosphor when the electron-beam energy ranges between 500 and 3500 eV. The nanoparticles exhibit less current saturation than larger-sized phosphors, an important feature for use in FEDs. Furthermore, the nanoparticles were annealed at just 535 °C, hundreds of degrees below the processing temperatures of standard phosphors. Finally, we discuss the effect of the particle surface on low-voltage luminous efficiency. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124518
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