The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with ~100 nm of Titanium Nitride (TiN). This is to minimize the secondary electron yield (SEY) from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Both DC sputtering and DCmagnetron sputte...

We consider methods to define the performance metrics for different plasmonic materials to be used in localized surface plasmon applications. Optical efficiencies are shown to be better indicators of performance as compared to approximations in the quasistatic regime. The near-field intensity efficiency, which is a generalized form of the wellknown scattering efficiency, is a more flexible and ...

Core-shell architectures offer an effective way to tune and enhance the properties of noble-metal catalysts. Herein, we demonstrate the synthesis of Pt shell on titanium tungsten nitride core nanoparticles (Pt/TiWN) by high temperature ammonia nitridation of a parent core-shell carbide material (Pt/TiWC). X-ray photoelectron spectroscopy revealed significant core-level shifts for Pt shells supp...

PURPOSE In this work we investigated the suitability of electroconductive silicon nitride/titanium nitride composite for biomedical implantable devices with particular attention on the processing route that allows the net-shaping of complex components by electrical discharge machining (EDM). METHODS The composite, constituted mainly of a beta-Si3N4, dispersed TiN grains and a glassy grain bou...

DENSE PERIODICAL PATTERNS IN PHOTONIC DEVICES:TECHNOLOGY FOR FABRICATION AND DEVICE PERFORMANCEbySABARISH CHANDRAMOHANDecember 2016 Advisor: Dr. Ivan AvrutskyMajor: Electrical EngineeringDegree: Doctor of Philosophy For the fabrication, focused ion beam parameters are investigated to successfullyfabricate dense periodical patterns, such as gratings, on hard transitio...

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| Gallium nitride (GaN) is one of the most important wide band gap semiconductor materials in modern technology with even higher expectations for future applications it is ought to play a crucial role. Among this, the growth of lattice and thermally matched GaN substrates for the GaN device technology takes an essential piece. This paper is reporting on the achievements in the ammonothermal gro...