Ferroelectric Domain Structure of La-modified Lead Titanate Ceramics
14 Dec 2018 | Contributor(s):: Brian Demczyk, G. Thomas
Presentation describes the ferroelectric domain structure of Lanthanum-modified lead titanate ceramics, as deduced by transmission electron microscopy, including the ferroelectric to paraelectric phase transformation. A significant result was the observation of a minimum grain size for...
Ferroelectric Domain Motion
07 May 2018 | Contributor(s):: Brian Demczyk
Videos show total ferroelectric domain disappearance in bulk La-doped lead titanate, and incomplete reversal in a small (< 0.5 micrometer) grain, when heated through the Curie point.
Magnetic Domain Reversal
Videos show magnetic domain disappearance and reappearance in a Co-22% Ct thin film when heated/cooled through the Curie Point.
Structure and Morphology of Silicon-Germanium Thin Films
07 Feb 2015 | Contributor(s):: Brian Demczyk
This presentation describes the growth of (Si,Ge & SiGe) thin films on Si and Ge (001) and (111) substrates by ultrahigh vacuum chemical vapor deposition (UHVCVD). Thin films were characterized structurally by conventional and high-resolution transmission electron microscopy (TEM) and...
Evolution of Microstructure and Magnetic Properties in CoCr Thin Films
25 Mar 2014 | | Contributor(s):: Brian Demczyk, J. O. Artman
This presentation describes the structural and magnetic properties, including domain structures, in magnetron-sputtered Co-25% Cr thin films.
Structure and Properties of Carbon and Boron Nitride Nanotubes
10 Jan 2014 | | Contributor(s):: Brian Demczyk
This presentation describes structure and mechanical property determinations on carbon and boron nitride (sp2-bonded) nanotubes , as deduced by transmission electron microscopy.
Structure and Morphology of Silicon Germanium Thin Films
30 Dec 2013 | | Contributor(s):: Brian Demczyk
Single layer silicon and germanium films as well as nominally 50-50 silicon-germanium alloys were deposited on single crystal silicon and germanium (001) and (111) substrates by ultrahigh vacuum chemical vapor deposition. These films spanned the range of + 4 % film-substrate lattice mismatch. A...
Corrosion Mechanisms in Magnetic Recording Media
29 Jul 2013 | | Contributor(s):: Brian Demczyk
This presentation describes the corrosion process in longitudinal and perpendicular recording media, based upon electron and scanning probe microscopic analysis.
Texture-Induced hcp c-axis Alignment in Longitudinal Media
15 Jul 2013 | | Contributor(s):: Brian Demczyk
This presentation discusses the development and measurement of c-axis text in longitudinal hard disk media.
On the Two to Three Dimensional Growth Transition in Strained Silicon Germanium Thin Films
02 Feb 2012 | | Contributor(s):: Brian Demczyk
Utilizing a model adapted from classical nucleation theory , we calculate a "critical thickness" for island formation, taking into account the surfaceenergies of the deposit and the substrate and the elastic modulus of the deposit, to which experimental results for CVD grown silicon germanium...
Boron Nitride Nanotube Growth Mode
27 Jan 2012 | | Contributor(s):: Brian Demczyk
This writeup details the growth details of arc-synthesized boron nitride nanotubes, incorporating the results of atomic resolution transmission electron microscopy, image simulation and image exit wave reconstruction techniques.This research was supported in part by the Director of the Office of...