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Full-Text Articles in Mechanical Engineering
Enhanced Purity Andresolution Via Laser Assistedelectron Beam Induced Deposition Of Platinum,, Nick A. Roberts, J. D. Fowlkes, G. A. Magel, P. D. Rack
Enhanced Purity Andresolution Via Laser Assistedelectron Beam Induced Deposition Of Platinum,, Nick A. Roberts, J. D. Fowlkes, G. A. Magel, P. D. Rack
Nick Roberts
We introduce a laser assisted electron beam induced deposition (LAEBID) process which is a nanoscale direct write synthesis method that integrates an electron beam induced deposition process with a synchronized pulsed laser step to induce thermal desorption of reaction by-products. Localized, spatially overlapping electron and photon pulses enable the thermal desorption of the reaction by-product while mitigating issues associated with bulk substrate heating, which can shorten the precursor residence time and distort pattern fidelity due to thermal drift. Current results demonstrate purification of platinum deposits (reduced carbon content by ~50%) with the addition of synchronized laser pulses as well as …
In Situ Laser Processing In A Scanning Electron Microscope, Nick Roberts
In Situ Laser Processing In A Scanning Electron Microscope, Nick Roberts
Nick Roberts
Laser delivery probes using multimode fiber optic delivery and bulk focusing optics have been constructed and used for performing materials processing experiments within scanning electron microscope/focused ion beam instruments. Controlling the current driving a 915-nm semiconductor diode laser module enables continuous or pulsed operation down to sub-microsecond durations, and with spot sizes on the order of 50 µm diameter, achieving irradiances at a sample surface exceeding 1 MW/cm2. Localized laser heating has been used to demonstrate laser chemical vapor deposition of Pt, surface melting of silicon, enhanced purity, and resistivity via laser annealing of Au deposits formed by electron beam …
Phonon Wave-Packet Simulations Of Ar/Kr Interfaces For Thermalrectification, Nick A. Roberts, D. G. Walker
Phonon Wave-Packet Simulations Of Ar/Kr Interfaces For Thermalrectification, Nick A. Roberts, D. G. Walker
Nick Roberts
The frequency and direction dependence of transmission coefficients at interfaces was investigated theoretically. The interfaces are formed by having two Lennard-Jones materials differing in mass and interatomic potential equally divided at the center of an fcc lattice system. A single frequency wave-packet is generated at one end of the system and allowed to propagate through the system until all interactions with the interface are complete. The transmission coefficient is then calculated by comparing the energy of the packet that is transmitted with the original wave-packet. Results show a difference in transmission when the wave-packet originates from opposite sides.