MVC 2 Awards Gallery

“BORON CARBIDE TITANIUM DIBORIDE“

Ryan White, Graduate Student, Materials Science and Engineering 

Scientific Process: This colorized transmission electron micrograph of a boron carbide (B4C) titanium diboride (TiB2) directionally solidified eutectic shows many important features of the as-grown in situ composite. The light (orange colorized) phase is boron carbide, which shows twinning throughout, represented by the sharp, angular lines of contrast near the top and center of the image. The twin lines are angularly separated by approximately 65 degrees, corresponding well to the definitive angle in the rhombohedral B4C crystal structure. Additionally, strain contrast can be seen throughout the B4C matrix, and specifically between the two TiB2 lamellae at the left center of the image. The strain between lamellae is due to differences in coefficient of thermal expansion, and the contrast in the TEM image can be correlated directly to tensile residual stress fields in B4C, caused by residual tension parallel to the long axis of the TiB2 lamellae. Image is 3.5 µm in width.

FIRST PLACE

“SALT CRYSTALS“

Julie Anderson, Researcher; Libby Kupp, Researcher; Gary Messing, Faculty, Materials Science and Engineering

Scientific Process: Water soluble salts have deliquescent points (i.e. a relative humidity above which they begin to dissolve in the moisture that is adsorbed on their surfaces). The salt crystals in this image were compacted and subsequently exposed to a controlled relative humidity above their deliquescent point. New structures re-crystallized at the particle interfaces. Maybe life really is like a box of chocolates!

SECOND PLACE

“MATRIX ASSISTED LASER DESORPTION IONIZATION“

Shivangi Nangia, Graduate Student, Department of Chemistry 

Scientific Process: Matrix Assisted Laser Desorption Ionization (MALDI) is an important analytical tool for studying the chemistry of bio-molecules like peptides and proteins. There is synergy between MALDI experiments and Molecular Dynamics (MD) simulations. To understand analyte ejection from the matrix, MD simulations have been employed. It is important to understand the factors that influence the embedding of the analyte in the matrix and its subsequent ejection. Our calculations analyze the influencing factors such as analyte size, interaction with the matrix, nearness to the sample surface, and sample preparation. The snapshot shows coarse grained matrix (2,5-dihydroxybenzoic acid, shades of orange) and analyte (Alanine, green) beads in the ejected plume at 700 ps after laser irradiation.

THIRD PLACE

“SEMICONDUCTOR WIRE ARRAYS“

Chito Kendrick, Post Doc, Materials Science and Engineering 

Scientific Process: Semiconductor wire arrays are being investigated for a cheaper and more efficient solar cell structure. To achieve the silicon wire arrays the vapor liquid solid growth mechanism is used where gold pads are spaced out in an array of pores etched into a SiO2 coated Si <111> wafer. In this image 2.5 µm pores were filled with a 300 nm thick gold layer and then grown on using an atmospheric chemical vapor deposition system with a silicon tetrachloride precursor at 1050°C. This resulted in silicon wires with diameters up to 1.8 µm and 4.5 µm pitch, the wires here have had their gold tips removed.

FIRST PLACE

“ION MILLED SINGLE CRYSTAL SILICON“

Brian Gauntt, Graduate Student, Materials Science and Engineering 

Scientific Process: The image is a transmission electron micrograph of ion milled single crystal silicon. The excessive ion milling resulted in an extremely thin sample that distorted into a wavy sheet. The silicon was not the focus of the investigation, but merely a substrate for a vanadium oxide thin film with application in infrared detection. While navigating the sample in the microscope I stumbled upon the wavy silicon and couldn’t help but capture a quick image. 

SECOND PLACE

“ION ETCHED SILICON PILLARS“

Xin Wang, Graduate Student, Electrical Engineering

Scientific Process: An array of radial p-n junction silicon pillars was fabricated using Deep Reactive Ion Etching (DRIE) and POCl3 diffusion. Following optical lithography to pattern 2ɥm circle array on a planar p-type (Boron doped) silicon wafer, DRIE was performed on the wafer for 15 minutes. POCl3, with O2 as the carrying gas, was used as the source for the n-type diffusion on the p-type pillar to form the radial p-n junction. 

THIRD PLACE

“TIO2 NANOTUBE ARRAY FILM“

Sorachon Yoriya, Graduate Student, Materials Science and Engineering

Scientific Process: The self-organized, highly ordered TiO2 nanotube array film of 10-μm length was fabricated by anodizing a titanium foil in a dimethyl sulfoxide (DMSO) electrolyte containing 2% v/v hydrofluoric acid (HF). The Ti foil was subjected to potentiostatic anodization at 40 V for 70 h, at room temperature of about 23°C, in a two-electrode electrochemical cell with a platinum foil as the counter electrode. After anodization, the as-anodized nanotube array film on the Ti substrate was washed with ethanol and blow-dried with nitrogen air. The thick fibrous layer covering the top surface of nanotube arrays can be easily removed by sonication, leaving behind the clearly open pores. After high temperature annealing, the crystallized TiO2 nanotube arrays offer great utilities in a variety of applications including gas sensors, dye-sensitized solar cells, photocatalytic reduction of CO2 under sunlight, and biomedical applications. The image size is 27.5 x 36.5 μm2.