Doug Vick - Academia.edu (original) (raw)

Papers by Doug Vick

Physical Review E, 1993

The formation and evolution of collisional structures in the coronas of laser-produced plasmas ha... more The formation and evolution of collisional structures in the coronas of laser-produced plasmas have been studied by irradiating multilayered targets with nonuniform laser beams. Spatially resolved x-ray emission patterns and spectra were recorded to infer the temperatures, ionization states, and timeintegrated hydrodynamic histories of plasmas originating from tracer layers embedded in the targets. The conditions of the experiment have been simulated using a two-dimensional single-Quid hydrodynamic code. The experimental results and code predictions are in good agreement, showing the stagnation of colliding plasmas in the nonirradiated regions.

Solid State Communications, 2014

A novel method for simultaneous detection of both DC and time-dependent magnetic signatures in in... more A novel method for simultaneous detection of both DC and time-dependent magnetic signatures in individual mesoscopic structures has emerged from early studies in spin mechanics. Multifrequency nanomechanical detection of AC susceptibility and its harmonics highlights reversible nonlinearities in the magnetization response of a single yttrium iron garnet (YIG) element, separating them from hysteretic jumps in the DC magnetization.

Ultramicroscopy, 2015

A new technique for the fabrication of highly sensitive qPlus sensor for atomic force microscopy ... more A new technique for the fabrication of highly sensitive qPlus sensor for atomic force microscopy (AFM) is described. Focused ion beam was used to cut then weld onto a bare quartz tuning fork a sharp micro-tip from an electrochemically etched tungsten wire. The resulting qPlus sensor exhibits high resonance frequency and quality factor allowing increased force gradient sensitivity. Its spring constant can be determined precisely which allows accurate quantitative AFM measurements. The sensor is shown to be very stable and could undergo usual UHV tip cleaning including e-beam and field evaporation as well as in-situ STM tip treatment. Preliminary results with STM and AFM atomic resolution imaging at 4.5 K of the silicon Si(111) − 7 × 7 surface are presented.

Langmuir, 2010

The high surface area, large aspect ratio, and porous nature of nanorod arrays make them excellen... more The high surface area, large aspect ratio, and porous nature of nanorod arrays make them excellent foundation materials for many devices. Of the many synthesis techniques for forming nanorods, glancing angle deposition (GLAD) offers one of the more straightforward and flexible methods for ensuring control of alignment, porosity, and architecture of the nanorods. Here we demonstrate the first use of a dual-beam (focused ion beam (FIB) combined with scanning electron microscopy (SEM)) instrument to section and image the internal morphology of a nanorod array fabricated using the GLAD technique. We have used the FIB-SEM to reconstruct the 3D composition of TiO 2 nanorods, allowing us to visualize for the first time the core structures of many potential devices. We have also been able to probe the relationship between critical parameters such as diameter (w hact), internanorod spacing (ν hact), center-to-center spacing (c act), and nanorod population density (d act) and the depth of the nanocolumn (t) for a single homogeneous structure. A continuous data set was obtained from a single 5-μm-thick GLAD film, avoiding the artifacts arising from the analysis of the top surfaces of multiple samples of varying thicknesses. An analysis of the acquired sectioned data has allowed us to determine that the critical nanocolumn parameters follow a power-law scaling trend with w hact =9.4t 0.35 nm, ν hact = 15.2t 0.25 nm, c act =24.8t 0.31 nm, and d act =3402t-0.65 columns μm-2. Using the FIB/SEM images acquired for the TiO 2 nanorods, we have also investigated the evolution of individual nanocolumns and have observed that bifurcation and branching play a significant role in the extinction or survival of these nanorods. These findings will allow for the optimization of nanorod properties for device applications. Also, the FIB sectioning and reconstruction process developed here will permit for the investigation of nanorod arrays formed from a range of synthesis techniques and materials.

Micron

We outline a public license (open source) electron microscopy platform, referred to as NanoMi. Na... more We outline a public license (open source) electron microscopy platform, referred to as NanoMi. NanoMi offers a modular, flexible electron microscope platform that can be utilized for a variety of applications, such as microscopy education and development of proof-of-principle experiments, and can be used to complement an existing experimental apparatus. All components are ultra-high vacuum compatible and the electron optics elements are independent from the vacuum envelope. The individual optical components are mounted on a 127 mm (5-inch) diameter half-pipe, allowing customizing of electron optics for a variety of purposes. The target capabilities include SEM, TEM, scanning TEM (STEM), and electron diffraction (ED) at up to 50 keV incident electron energy. The intended image resolution in SEM, TEM and STEM modes is ≈ 10 nm. We describe the existing components and the interfaces among components that ensure their compatibility and interchangeability. The paper provides a resource for those who consider building or utilizing their own NanoMi.

Microscopy and Microanalysis, 2021

Optica, 2018

Silicon is widely used as the material of choice for semiconductor and insulator applications in ... more Silicon is widely used as the material of choice for semiconductor and insulator applications in nanoelectronics, microelectro-mechanical systems, solar cells, and on-chip photonics. In stark contrast, in this paper, we explore silicon's metallic properties and show that it can support propagating surface plasmons, collective charge oscillations, in the extreme ultraviolet (EUV) energy regime not possible with other plasmonic materials such as aluminum, silver, or gold. This is fundamentally different from conventional approaches, where doping semiconductors is considered necessary to observe plasmonic behavior. We experimentally map the photonic band structure of EUV surface and bulk plasmons in silicon using momentum-resolved electron energy loss spectroscopy. Our experimental observations are validated by macroscopic electrodynamic electron energy loss theory simulations as well as quantum density functional theory calculations. As an example of exploiting these EUV plasmons for applications, we propose a tunable and broadband thresholdless Cherenkov radiation source in the EUV using silicon plasmonic metamaterials. Our work can pave the way for the field of EUV plasmonics.

Microscopy Research and Technique, 2012

Microscopy and Microanalysis

We are developing a modular (scanning) transmission electron microscope (S)TEM, referred to as Na... more We are developing a modular (scanning) transmission electron microscope (S)TEM, referred to as NanoMi, which is released under an open source license [1] by the National Research Council, Canada; see [2] for updates.

AIP Advances

Achieving μeV tunneling resolution in an in-operando scanning tunneling microscopy, atomic force ... more Achieving μeV tunneling resolution in an in-operando scanning tunneling microscopy, atomic force microscopy, and magnetotransport system for quantum materials research Review of Scientific Instruments 91, 071101 (2020);

Lettere Al Nuovo Cimento Series 2

ABSTRACT

Il Nuovo Cimento B, Jul 1, 1986

The gravitational collapse of a spherical conducting shell subject to the repulsive Casimir force... more The gravitational collapse of a spherical conducting shell subject to the repulsive Casimir force is considered. The question of whether the Casimir effect can prevent the collapse of the shell down to zero radius is raised with particular reference to the previous work on this topic done by Brevik and Kolbenstvedt. In contrast to this earlier treatment, the simplest consistent model exhibits features similar to the charged-shell case. In such a model, the Casimir force is unable to arrest the collapse if the shell's mass exceeds a microscopic value.

Journal of Vacuum Science and Technology a Vacuum Surfaces and Films, Nov 1, 2002

ABSTRACT We describe the fabrication of porous chevron thin films deposited at glancing incidence... more ABSTRACT We describe the fabrication of porous chevron thin films deposited at glancing incidence and report some common growth peculiarities of the microstructure. In particular, the second (and additional) chevron arms of porous chevron thin films are consistently inclined at angles significantly greater than the corresponding first arms. This effect is observed in both real and simulated films and has important implications in the fabrication of optical coatings. A simple theoretical model is developed to describe this effect, and a technique for achieving consistent column angles is presented. © 2002 American Vacuum Society.

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1999

ABSTRACT A nanoindentation technique has been applied to demonstrate the mechanical actuation of ... more ABSTRACT A nanoindentation technique has been applied to demonstrate the mechanical actuation of thin films fabricated by glancing angle deposition. The films were comprised of a porous layer whose microstructures consisted of helical columns that resembled springs. Surmounting the porous layer was a dense capping layer which served to redistribute the force of the nanoindenter tip and prevent it from penetrating the microstructured film. Atomic force microscope images and force versus displacement curves confirmed that there was an elastic regime to the displacements in the films when low forces were applied. The loading behavior of the porous films was compared with that of dense, unstructured films and revealed a marked difference between the two. A study of the measurements and results enabled such properties as the spring constant and resonant frequencies to be estimated, establishing a basis for future developments and applications in wave-type devices or resonators constructed from these microstructured thin films. © 1999 American Vacuum Society.

2004 International Conference on MEMS, NANO and Smart Systems (ICMENS'04), 2004

Abstract The ability to produce high aspect ratio particle aerosols (airborne fibres) is required... more Abstract The ability to produce high aspect ratio particle aerosols (airborne fibres) is required in order to develop a thorough understanding of the parameters that affect the deposition of fibres in the mouth and throat. Such an ability is currently being developed. ...

Thin Solid Films, 1999

Pulsed laser deposition (PLD) has been used together with the Glancing Angle Deposition (GLAD) te... more Pulsed laser deposition (PLD) has been used together with the Glancing Angle Deposition (GLAD) technique [1,2] for the first time to produce highly porous structured films. A laser produced carbon plasma and vapour plume was deposited at a highly oblique incident angle onto rotating Si substrates, resulting in films exhibiting high bulk porosity and controlled columnar microstructure. By varying the substrate rotation rate, the shape of the microcolumns can be tailored. These results extend the versatility of the GLAD process to materials not readily deposited by means of traditional physical vapour deposition techniques.

2005 International Conference on MEMS,NANO and Smart Systems, 2005

In toxicology and industrial hygiene, fibrous aerosols have long been associated with health risk... more In toxicology and industrial hygiene, fibrous aerosols have long been associated with health risks. Aerodynamic alignment with inhaled air streamlines allows long, cylindrical fibers to penetrate deep into the lung, whereas compact particles of similar mass are filtered out in the upper respiratory tract. For drug delivery applications, fibrous aerosols may thus enable a relatively large drug mass to be

Engineered Nanostructural Films and Materials, 1999

Glancing angle deposition: recent research results. [Proceedings of SPIE 3790, 114 (1999)]. Micha... more Glancing angle deposition: recent research results. [Proceedings of SPIE 3790, 114 (1999)]. Michael J. Brett, Mary W. Seto, Jeremy C. Sit, Ken D. Harris, Doug Vick, Kevin Robbie. Abstract. Unique thin film microstructures have ...