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We discuss the experimental results of a method for generation of nonthermal plasma at atmospheric pressure. The device uses two chambers separated by a dielectric. A low-pressure chamber produces UV emission, which is coupled to the atmospheric pressure discharge. The electrical and optical characteristics of this device are discussed. Results show that the dual-chamber discharge is more uniform compared to conventional dielectric-barrier discharges.

We have shown that dielectric/metal composite nanowires exhibit very strong surface enhanced Raman spectroscopy (SERS) signals when arranged in a random three-dimensional geometry. Since the intersections of the nanowires are critical in generating the high electric fields necessary for this enhancement, we are investigating this effect under more controlled conditions. We examined nanowire arrays formed by e-beam lithography and we have examined the plasmonic effects, both longitudinal and transverse, due to changes in crossing geometry by specific placements of dielectric/metal nanowires on these arrays. Results indicate significant angular effects on the SERS enhancement supported by electric field calculations.

Recently, the authors have shown that dielectric/metal composite nanowires exhibit very strong surface enhanced Raman (SERS) signals when arranged in a random three-dimensional geometry. Since they believe that the intersections of nanowires are critical in generating the high electric fields necessary for this enhancement, they have investigated the effect of crossing geometry under more controlled conditions. Thus, they will discuss the formation of nanowire arrays by in situ growth achieved by the control of nanowire material/substrate combination, as well as ex situ nanowire array formation involving e-beam lithography. They have examined the plasmonic effects, both longitudinal and transverse, due to changes in crossing geometry by specific placements of dielectric/metal nanowires on the fabricated arrays. The effects of nanowire geometry and the resulting SERS behavior show the importance of the dielectric/metal configuration, as well as the importance of nanowire angular geometry in the SERS enhanc...

The Si wires were grown on a Si(111) substrate using the pulsed laser deposition system. Gold was used as a metal catalyst to form the silicon wires utilizing the vapor-liquid-solid growth mechanism. Samples were grown under ultrahigh vacuum conditions at a growth temperature of 800 °C. Typical dimensions of the grown Si wires were 200–500 nm in diameter and 1.6 μm in height.

It is shown that a molecular field model of ferroelectrics can explain the observed fact that p/(e - l)1/2, and hence D*, is practically independent of temperature and of the material. The calculated values of p/(e - l)½ are relatively close to the experimental values. A class of ferroelectrics is defined that may give larger values of p/(e - l)½ and hence larger values of D*.

The factor ρ/(e - 1)½ is calculated for the case of displacement type ferroelectrics; its value corresponds closely to what was found for the dipole model of ferroelectrics.

It is shown that for a two-level ferroelectric model the thermal noise comes about by partition noise between the two energy levels.