18,708 research outputs found

    Sequence of phase formation in planar metal-Si reaction couples

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    A correlation is found between the sequence of phase formation in thin-film metal-Si interactions and the bulk equilibrium phase diagram. After formation of the first silicide phase, which generally follows the rule proposed by Walser and Bené, the next phase formed at the interface between the first phase and the remaining element (Si or metal) is the nearest congruently melting compound richer in the unreacted element. If the compounds between the first phase and the remaining element are all noncongruently melting compounds (such as peritectic or peritectoid phases), the next phase formed is that with the smallest temperature difference between the liquidus curve and the peritectic (or peritectoid) point

    Thin film contact resistance with dissimilar materials

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98706/1/JApplPhys_109_124910.pd

    Extraction of ions from the matrix sheath in ablation-plasma ion implantation

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    A simple one-dimensional theory is presented to assess the implantation of ions from the ion matrix sheath (IMS) in an ablated plasma plume that is approaching a negatively biased substrate. Under the assumption that the plume geometry, the electron and ion density distributions, and the potential distribution are frozen during the IMS extraction, the implanted ion current is calculated as a function of time for various substrate-plume separations. This model accurately recovers Lieberman’s classic results when the plume front is initially in contact with the substrate. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70969/2/APPLAB-78-6-706-1.pd

    Microwave absorption on a thin film

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    With the use of a simple model, it is shown that a thin film of contaminant on a microwave window may absorb up to 50% of the incident power, even if the film thickness is only a small fraction of its resistive skin depth. This unexpectedly large amount of absorption is conjectured to have played a significant role in window failure. The temperature rise in a thin film is estimated. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71216/2/APPLAB-82-9-1353-1.pd

    Heating of Contaminants on Diamond Windows

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    This paper examines the RF heating of the contaminants on a diamond window. Both heating of an isolated internal graphite impurity, and of a thin film on the window surface, are discussed. Comparison with recent experiments is given. It is found that heating of isolated internal graphite impurities is unlikely to account for diamond window failure. Upon averaging over the entire window, the thin surface film in general absorbs approximately a fraction of one percent of the total incident power. Intense local heating on the surface contaminant is possible, however. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87504/2/234_1.pd

    Low-noise microwave magnetrons by azimuthally varying axial magnetic field

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    A technique has been demonstrated to significantly reduce the noise in microwave oven magnetrons. The technique employs permanent magnets to generate an azimuthally varying axial magnetic field. Noise measurements are reported which show dramatic reductions in the noise of kW oven magnetrons operating near 2.45 GHz. The noise reduction near the carrier is some 30 dB. Microwave sidebands are reduced or eliminated. Noise reduction occurs at all anode currents, but is particularly significant at low current near the start-oscillation condition. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70840/2/APPLAB-83-10-1938-1.pd

    Resonant absorption of a short-pulse laser in a doped dielectric

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    A simple model is used to calculate the energy absorption efficiency when a laser of short pulse length impinges on a dielectric slab that is doped with an impurity with a resonant line at the laser frequency. It is found that the energy absorption efficiency is maximized for a certain degree of doping concentration (at a given pulse length) and also for a certain pulselength (at a given doping concentration). Dimensionless parameters are constructed, allowing calculations with one set of parameters be used to infer the results expected for other sets of parameters. © 1999 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70124/2/APPLAB-74-20-2912-1.pd
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