Bulletin of the American Physical Society
2006 Texas Section of the APS Joint Fall Meeting
Thursday–Saturday, October 5–7, 2006; Arlington, Texas
Session FIAP1: Industrial and Applied Physics |
Hide Abstracts |
Chair: Stefan Zollner, Freescale Semiconductor, Inc. Room: UT Arlington, University Center Guadalupe |
Friday, October 6, 2006 1:30PM - 1:42PM |
FIAP1.00001: Enhanced Nanotribology and Optimal Self-lubrication in Novel Polymer-Metal Composites Alisha Seam, Witold Brostow, Oscar Olea-Mejia Cheaper to produce, light-weight polymeric materials with improved micro and nano-scale tribological characteristics ar gradually replacing the heavier metals in gears, cams, ball-bearings, chains, and other critical machine components which operate under high stress, experience substantial sliding friction and wear, and require external lubrication regimes. Application of such high-performance synthetic materials in a whole range of machinery, manufacturing, aerospace and transportation industries would produce far reaching economic, energy conservation and environmental benefits. This paper devises and investigates a novel and previously untested method of developing self-lubricating and wear-resistant polymer based materials (PBMs) by blending a polymer with small proportions of a metallic additive. Tribological experiments establish that as increasing proportions of the metallic additive Iron (Fe) are added to the polymeric base polyethylene (PE), the friction and wear of the resulting composite (PE-Fe) experiences significant decline until an optimal value of 3 to 5 {\%} Iron and then stabilize. Theoretical analysis reveals this phenomenon to likely be a result of the nano-structural formation of a lubricating oxide layer on surface of the polymer-metal composite. Furthermore, the oxide layer prevented significant degradation of the viscoelastic scratch-recovery of the base polymer, even with 10 percent metal additive (Fe) in the composite samples. [Preview Abstract] |
Friday, October 6, 2006 1:42PM - 1:54PM |
FIAP1.00002: Theoretical investigation of phase transitions in hafnia Xuhui Luo, A.A. Demkov Transition metal (TM) oxides find applications in ceramics, catalysis and semiconductor technology. In particular, hafnium dioxide or hafnia will succeed silica as a gate dielectric in advanced CMOS devices. However, the thermodynamics properties of thin TM oxide films are not well understood, despite their technological importance. Studying the details of phase transitions in hafnia experimentally is difficult due to their extremely high temperature. We have studied theoretically the phase transitions in hafnia using density functional theory. First we investigate the stability of the cubic phase of hafnia and find it unstable (transforming without a barrier to a tetragonal phase \textit{via} a soft-phonon mode) in agreement with experiment. However, for low symmetry structures the full phonon mode analysis is rather complicated and other means of generating phase transition pathways need to be employed. We use the nudged elastic band method (NEBM) to find the transition path and estimate the energy barrier along it. In the case of the cubic to tetragonal phase transition NEBM finds the same soft-mode path and no barrier in agreement with the previous calculations. Using NEBM we are able to identify the pathway for the tetragonal to monoclinic phase transition, and find a 0.2 eV barrier. This work is supported by the National Science Foundation under contract DMR-0606464. [Preview Abstract] |
Friday, October 6, 2006 1:54PM - 2:06PM |
FIAP1.00003: Evolution of Ni on Si after thermal annealing observed with XRR Stefan Zollner, D. Jawarani, S. Bolton, K. Chang, R. Noble, M. Jahanbani, M. Rossow The self-aligned silicide module of a CMOS process requires cleaning the silicon surface, metal deposition, thermal annealing, and selective removal of the unreacted metal by wet- chemical etching, followed by a final thermal annealing step to reduce the electrical resistivity. We have followed the evolution of sputtered Ni films with 10 nm thickness on Si (100) through these process steps with x-ray reflectivity (XRR). Both HF wet clean and in situ plasma clean produce NiSi films with similar properties. We also did not find a significant impact of the anneal method. Films annealed at 360C for 5s or at 320C for 30s produced similar XRR spectra. However, Ni films deposited on Si after an in situ RF sputter etch with Ar ions have a low-density voided region below the surface, which cannot be removed by annealing. A similar intermediate layer is reported in the literature when annealing Pt on Si in an oxygen-containing ambient. Transistors produced with NiSi contacts have undesirable characteristics (leakage) if the substrate is cleaned by RF etch prior to Ni deposition. Most likely, the RF sputter edge encourages the formation of NiSi2 pyramids at very low temperatures ($<400^{\circ}$C) or the diffusion of Ni from the source-drain regions of the transistor into the channel. [Preview Abstract] |
Friday, October 6, 2006 2:06PM - 2:18PM |
FIAP1.00004: Diffusion of Silver in DC plasma prepared Diamond Like Carbon Films Yudong Mo, Philip Ecton, Andrew Ballinger, Hersh Mahajan, Allen Chang, David Garrett, Morgan Lynch, Jose Perez, Vaishali Ukirde, Mohamed El Bouanani Diamond like carbon (DLC) films were grown using DC plasma deposition (PECVD) of Argon/Methane gas mixtures of 5-8{\%} methane. Both Scan Electron Microscopy (SEM) and Raman Spectroscopy were used to characterize and optimize the DLC deposition. A silver film with a thickness of approximately 15 nm was deposited on the DLC films prior to annealing in flowing nitrogen in the temperature range 400C-900C. Rutherford backscattering Spectrometry was used to determine the silver diffusion profiles in DLC and extract its diffusion characteristics. [Preview Abstract] |
Friday, October 6, 2006 2:18PM - 2:30PM |
FIAP1.00005: Tribological and thermal properties of blends of melamineformaldehyde resins with low density polyethylene Bernard Huang, Witold Brostow, Tea Datashvili Melamine + formaldehyde resin (MFR) was synthesized and blended with a low density polyethylene (LDPE). Tribological, thermal and morphological properties of LDPE + MFR blends containing 1, 5, 10, 20, 25 wt. {\%} MFR were investigated. After preparing the blends with a Brabender preparation station and a compression molding machine, the following properties were determined: wear rate and friction, sliding wear and microhardness. Thermal properties had been analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). A detailed study on the miscibility behaviour of the blends has been made by using Fourier transform infrared spectroscopy (FTIR), environmental scanning electron microscopy (ESEM) and atomic force microscopy (AFM). The morphological observations are correlated with the properties. Thermal analysis, AFM and ESEM support the presence of a partial compatibilization. [Preview Abstract] |
Friday, October 6, 2006 2:30PM - 2:42PM |
FIAP1.00006: The Relationship between the DC Bias and Debye Length in a Complex (Dusty) Plasma James Creel, Jie Kong, Truell Hyde Dust particle levitation height within the plasma sheath is known to be related to the background pressure, DC bias, and Debye length. A new experimental technique has been shown to yield the Debye length based on changes in particle levitation height due to an externally applied variable DC bias. This method for evaluation of the Debye length seems simpler to implement in some cases when compared to those methods currently in practice. [Preview Abstract] |
Friday, October 6, 2006 2:42PM - 2:54PM |
FIAP1.00007: Dental obturation materials Elizabeth Stockton, Lauren Chudej, Brian Bilyeu, Witold Brostow During the last decades, people have tried to develop a better material for use in dental obturation materials. This new material should meet the following requirements: durability, wear resistance, biocompatibility and chemical adhesion to dentin enamel. Wear resistance is very important and it is related with the service life of dental replacements. We have obtained aesthetically promising novel nano composites that can be used as dental replacements. The main objective of this work is to study the scratch and wear resistance of these nano composites. To meet this goal, scratch tests are performed using a micro scratch tester machine (CSEM), where a diamond indenter is used to make the scratch and the penetration of this indenter is measured with high resolution (7nm). We will be looking at the penetration depth (R$_{p})$ and the residual (or healing) depth (R$_{h})$ to calculate the percent recovery. These measurements represent the scratch resistance of the material. [Preview Abstract] |
Friday, October 6, 2006 2:54PM - 3:06PM |
FIAP1.00008: Tribology of polymer surfaces: Effects of plasma treatment Rachel Chiu, Witold Brostow, Haley E. Hagg Lobland, Alexander Bismarck, Kingsley K.C. Ho We have subjected several polymers with a large variety of chemical structures to plasma treatment for varying amounts of time. The effects of the treatment have been followed in terms of the water wetting angle (hydrophilicity), static and dynamic friction, scratch resistance and sliding wear. Some polymers do not undergo significant changes as a result of the interaction with plasma. However, other polymers show more pronounced and useful effects, such as a lowering of dynamic friction as in polycarbonate and polypropylene or a higher scratch resistance, mainly in low density polyethylene. These results can be explained in terms of the chemical structures and resulting degree of hydrophilicity. [Preview Abstract] |
Friday, October 6, 2006 3:06PM - 3:18PM |
FIAP1.00009: Modeling the Efficiency of a Germanium Detector Keith Hayton, Michelle Prewitt, C.A. Quarles We are using the Monte Carlo Program PENELOPE and the cylindrical geometry program PENCYL to develop a model of the detector efficiency of a planar Ge detector. The detector is used for x-ray measurements in an ongoing experiment to measure electron bremsstrahlung. While we are mainly interested in the efficiency up to 60 keV, the model ranges from 10.1 keV (below the Ge absorption edge at 11.1 keV) to 800 keV. Measurements of the detector efficiency have been made in a well-defined geometry with calibrated radioactive sources: Co-57, Se-75, Ba-133, Am-241 and Bi-207. The model is compared with the experimental measurements and is expected to provide a better interpolation formula for the detector efficiency than simply using x-ray absorption coefficients for the major constituents of the detector. Using PENELOPE, we will discuss several factors, such as Ge dead layer, surface ice layer and angular divergence of the source, that influence the efficiency of the detector. [Preview Abstract] |
Friday, October 6, 2006 3:18PM - 3:30PM |
FIAP1.00010: Glass transition temperatures as a function of composition in binary systems: Poly(ethylene oxide) + epoxy system Vincent Paris, Witold Brostow, Ioannis Kalogeras, Aglaia (Lila) Vassilkou-Dova The glass transition temperatures (T$_{g})$ of PEO + epoxy resin blends in the full concentration range were analyzed. They were obtained by differential scanning calorimetry (DSC) and thermally stimulated current (TSC) depolarization. We have focused on the deviation from a linear relationship defined as $\Delta $T$_{g }$= T$_{g }$-X$_{A}$T$_{g,A}$ -X$_{B}$T$_{g,B }$, where T$_{g}$ is the glass transition temperature of the blend, X$_{i}$ is the weight fraction of $i$ component in the blend, while T$_{g, i}$ is the glass transition temperature of the $i$ component. A new equation for the Tg as a function of concentration was developed, based on an analysis of $\Delta $T$_{g}$. The results predicted with the new equation are better than those from the earlier T$_{g}$ equations, such as the Kwei equation, the Gordon-Taylor equation, and the Fox equation. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700