Papers by Author: Shuang Lin Yue

Abstract: Nanoscaled silicon cone arrays were formed on mirror-polished silicon wafers by plasma etching using hot filament chemical vapor deposition (HFCVD) system. A mixture of CH4 and H2 was introduced during silicon cone formation. AlN films were coated on Si cone arrays using radio frequency (RF) magnetron sputtering system. Scanning electrons microscopy (SEM) was employed to characterize the morphology of silicon cone arrays before and after AlN coating. The field emission characteristics of AlN coated silicon cone arrays，uncoated silicon cone arrays and AlN films were studied and compared, and the silicon cone arrays with AlN coating showed the best enhanced electron emission properties due to the negative electron affinity of AlN coating layer and the high aspect ratio of silicon cone. For AlN coated silicon cone arrays, a slight hysteresis between the upward and downward voltage sweeps was also observed and the field emission currents from AlN coated Si nanocone arrays decreased with the increase of the thickness of AlN films, which could be mainly attributed to the space charge buildup in AlN film with wide band gap.

Abstract: In the emerging field of nanobiotechnology, further downsizing the fluidic channels and pores to the nanometer scale are attractive for both fundamental studies and technical applications. The insulation Silicon nitride membrane nanofluidic channel arrays which have width ~50nm and depth ~80nm and length ≥20μm were created by focused-ion-beam instrument. The λ-DNA molecules were put inside nanochannels and transferred, a fluorescence microscopy was used to observe the images. Only by capillary force, λ-DNA molecules moved inside the nanochannels which dealt with activating reagent Brij aqueous solution. These scope nanostructure devices will help us study DNA transporting through a nanopore and understand more DNA dynamics characteristics.

Abstract: By using radio frequency magnetron reactive sputtering system, (002)-oriented AlN film was deposited on W tip. The field emission from (002)-oriented AlN film on W tip was studied and compared with that from the bare W tip in a high vacuum (≤10-6 Pa) chamber. It indicated that the enhanced electron emission could be obtained from the (002)-oriented AlN film on W tip. The corresponding Fowler-Nordheim plot of AlN presented a nonlinear behavior in nature related the high resistivity of AlN. Furthermore, the current-electric field (I-E) curve presented excellent reproducibility checked by repeated measurements.

Abstract: In this study, isothermal torsion tests were carried out on magnesium AZ31B alloy under constant strain rate conditions, in the range of 250 to 400oC at 0.01, 0.1, and 1.0 s-1. Alloy flow stress dependence on strain rate and temperature can be described by a power law with activation energy of 130 kJ/mol. Microstructural examination of hot deformed samples shows very fine recrystallized grains decorating grain boundaries of larger gains in the form of a necklace. These fine grains are produced by dynamic recrystallization at the grain boundaries of original grains. Microstructure evolution, based on samples quenched at different strain levels, indicates that increasing deformation strain has little effect on recrystallized grain size but widens the recrystallized region, with full recrystallization achieved at a certain high strain level. Recrystallized grain size increases with increasing deformation temperature and strain rate. The latter suggests recrystallization in AZ31 to be essentially a time dependant phenomenon.