An Analysis of the Affected Behavior of PVDF due to Various Backing Materials. WINSTON LYONS III (South Mountain Community College Phoenix, AZ 85042) JASON BARTLETT (City College of San Francisco San Francisco, CA 94117) DR. MORRIS S. GOOD (Pacific Northwest National Laboratory, Richland, WA, 99352) MICHAEL KINTNER-MEYER (Pacific Northwest National Laboratory, Richland, WA, 99352)

PVDF film is a piezoelectric material capable of sending or receiving a broad range of frequencies when used as an ultrasonic signal interpreter. This article addresses the questions of how different backing materials affect this characteristic of PVDF and whether or not that effect is dependent upon the film's thickness. Using a general material testing matrix, a series of transmitters were constructed for empirical experiments to qualitatively probe for the answers. Fourier transforms were derived from each transmitter by two different methods and compared to determine the exact effects the different backing materials have upon the PVDF's transmittance properties. Using the air backed data as a standard, each tested backing material is compared and discussed in relative terms. Also, all relevant graphs are provided.

Comparison of "ridge" like structures induced by light and heavy ions on single crystal SrTiO3 surfaces using MeV implantation. LEE REAM (Yakima Valley Community College Yakima, WA 98908) V. SHUTTHANANDAN (Pacific Northwest National Laboratory, Richland, WA, 99352)

The understanding of nano-structures has become increasing interest due to their applications in several areas. In particular, there is a high demand for high surface area nano-structures oxide materials due to their applications in heterogeneous catalysis. It has been recently showed that periodic "ridge" like structure with high surface area can be synthesized on SrTiO3 single crystal surface by grazing angle ion implantation. In the present work, influence of the mass of incident ions on these ridge like structures were systematically studied using Rutherford backscattering spectrometry (RBS), Proton Induced X-ray Emission (PIXE), scanning electron microscopy (SEM), and energy dispersive x-ray emission (EDX). Heavy (Gold) and light (nickel) ions with different ion doses and energies were implanted at grazing angle direction to the surface at 300 K in SrTiO3 (100) single crystal surfaces. Measurements of the samples were conducted directly after implantation. RBS measurements from the sample implanted with gold show that the gold is uniformly distributed to a depth of 400 nm from the surface. Total dose of implanted gold and nickel were obtained by PIXE. SEM micrographs obtained from these samples show that the surface of the implanted region underwent substantial rearrangement and formed "ridge" like structures. These "ridge" like structures are periodic in nature with wavelengths ranging from 0.5 to 4 microns and formed throughout the implanted region with the average heights of 0.2 to 4 microns. SEM micrographs further reveled that there is a strong correlation exists between the directions of the ridges and the mass of the incident ion beam. It was noticed that with the heavy ions the ridges that formed were parallel to the beam. While, with the light ions, the ridges formed perpendicular to the direction of the incident ion beam.

Cross-Correlation of Thermal and Optically Induced Structural Changes in Arsenic Trisulfide Thin Films. VERONICA AUGUSTYN (University of Arizona Tucson, AZ 85719) S.K. SUNDARAM (Pacific Northwest National Laboratory, Richland, WA, 99352)

Chalcogenide glasses (based on S, Se, Te) exhibit dramatic photoinduced changes in their physical and optical properties. These phenomena can used to create a variety of integrated photonic structures through controlled, localized, changes in the refractive index of the glass. However, successful application of such photo-modified structures requires that these glasses are stable under service conditions. Understanding the structural modification processes in these materials is central to successfully exploiting their photosensitivity as well as maximizing their environmental stability. The present study examines the effect of both thermal and optical exposures on the optical and structural characteristics of As₂S₃ evaporated thin films. Thin film samples were exposed to different environments and analyzed using optical absorption and X-ray diffraction (XRD). A red-shift of over 5 nm was observed in the optical absorption edge for samples stored for up to 15 days in a controlled environment chamber (50 C, 72% relative humidity) and illuminated by a light emitting diode (LED) at 507 nm. A similar shift in the absorption edge was also observed after annealing the as-deposited films at increasing temperatures (110 C, 130 C, 150 C, and 170 C). An additional shift in the absorption edge of the thermally annealed specimens was observed in the films after subsequent optical exposure (100 J/cm² total fluence) at 514 nm. All absorption edge shifts were correlated with structural modifications observed using XRD that indicated the as-deposited short-range, realgar-based, structural units (As₄S₄) were converted to orpiment (As₂S₃) moities. The corresponding changes in refractive index in the thermally annealed films were obtained from an analysis of the interference fringes in the absorption spectra. The refractive index of the film was found to increase with increasing annealing temperature, reaching a maximum of + 0.14 at a wavelength of 1000 nm after treatment at 170 C. The results indicate that both optical and thermal exposures activate similar structural modification processes in the films. These changes in structural configuration are consistent with the relaxation of the high-energy structural states in the thermally evaporated material.

Cross-Correlation of Thermal and Optically Induced Structural Changes in Arsenic Trisulfide Thin Films. HELEN FAN (University of Arizona Tucson, AZ 85719) S.K. SUNDARAM (Pacific Northwest National Laboratory, Richland, WA, 99352)

Chalcogenide glasses (based on S, Se, Te) exhibit dramatic photoinduced changes in their physical and optical properties. These phenomena can provide the basis for the optical patterning of refractive index to fabricate useful optical device structures in the glass for a variety of integrated photonic applications. In addition, these glasses need to be stable in service conditions. Understanding structural modification processes in these materials is central to successfully exploiting their photosensitivity as well as maximizing their environmental stability. The present study examines the effect of both thermal and optical exposures on the optical and structural characteristics of As₂S₃ evaporated thin films. Thin film samples were exposed to one of two different environments and their resulting optical absorption and X-ray diffraction (XRD) results were compared. A red-shift of over 5 nm was observed in the optical absorption edge for samples stored for up to 15 days in a controlled environment chamber (50 C, 72 % relative humidity) and illuminated by a light emitting diode (LED) at 507 nm. A similar shift in the absorption edge was also observed after annealing the as-deposited films at increasing temperatures (110 C, 130 C, 150 C, and 170 C). An additional shift in the absorption edge of the thermally annealed specimens was observed in the films after subsequent optical exposure (100 J/cm² total fluence) at 514 nm. All absorption edge shifts were correlated with structural modifications observed using XRD that indicated the conversion of short-range, realgar-based structural units (As₄S₄) to orpiment (As₂S₃). The corresponding changes in refractive index in the thermally annealed films were obtained from an analysis of the interference fringes in the absorption spectra. The film index was found to increase with increasing annealing temperature, reaching a maximum of +0.14 at a wavelength of 1000 nm after treatment at 170 C. The results indicate that both the optical and thermal exposures activate similar structural modification processes in the films. These changes in structural configuration are consistent with the relaxation of the high-energy structural states in the thermally evaporated material.

Elevated Temperature Compression Properties of Unirradiated V-4Cr-4Ti. MICHAEL FRYD (Lawrence University Appleton, WI 54911) MYCHAILO TOLOCZKO (Pacific Northwest National Laboratory, Richland, WA, 99352)

V-4Cr-4Ti is a potential structural material currently being investigated for post-ITER fusion reactor concepts. Vanadium alloys are attractive because of their relative resilience to becoming radioactive and their resistance to high temperature creep. To obtain information on the deformation properties of this material, compression tests of cylindrical unirradiated 3 mm diameter by 3.5 mm tall specimens from heats 832665 and NIFS-1 were performed at 250 C and ~415 C at a strain rate of 5x10^-4 s^-1. The yield stress for the NIFS-1 heat was 222 MPa at 250 C and 213 MPa at ~415 C. Yield stress for heat 832665 was 244 MPa at 250 C and the average yield stress was 236 MPa at ~415 C. The power law strain hardening (PLSH) exponent for the NIFS-1 heat was 0.28 at 250 C and 0.34 at ~415 C. The PLSH exponent for heat 832665 was 0.3 at 250 C and 0.27 at ~415 C.

Method for Creating Gradient Porosity in Sintered Nickel Components. MORGAN POLIKOFF (University of Illinois at Urbana Champaign Urbana, IL 61801) K. SCOTT WEIL (Pacific Northwest National Laboratory, Richland, WA, 99352)

Titanium is widely used for orthopedic implants, due to its biocompatibility and high strength-to-weight ratio. In recent years, interest has been shown in creating titanium components with a graded porous microstructure. With greater porosity in the center of the part and higher density in the edges, the components would more closely replicate the properties of natural bone. The goal of the present study was to establish processing techniques for producing sintered metal bodies with graded porosity. As a surrogate for titanium, nickel was chosen for its inertness to carbon, nitrogen, and oxygen impurities and ease of sintering. A binder system of naphthalene, stearic acid, and ethylene vinyl acetate was mixed with nickel powder to allow the pre-sintered body to be shaped by pressing. The use of a naphthalene-based binder system is advantageous because the naphthalene can be sublimed at low temperatures (~60-80ºC). In combination with controlled drying and cold isostatic pressing (CIP) protocol, the use of naphthalene allows the porosity of the body to be tailored. Spherical, 400 mesh nickel powder was mixed with the binder system in 45%, 55%, 60%, and 65% ratios by volume and pressed into discs. The discs were subjected to drying and CIP under varying conditions. The working hypothesis was that by subliming different amounts of naphthalene from the discs in a vacuum oven before CIP, the sintered nickel components would exhibit varying degrees of gradient porosity. Inadequate green strength of the partially de-bindered nickel discs was a problem initially, but this was overcome by carrying out an initial CIP step before de-bindering. After a series of drying curves was established for the discs at different temperatures, the discs were CIPed and sintered in a high-temperature furnace. The data revealed a positive correlation between final density and naphthalene removal - as more naphthalene was removed from the samples prior to CIP, the final density increased. Also, with decreased nickel loading in the initial mixture, final density decreased. Metallurgical analysis will be conducted on the sintered samples to determine their porosity and examine their cross-sectional microstructure. Future study will focus on the use of a modified naphthalene-based binder system, as well as an effort to enlarge the pores by employing nickel carbonate in place of pure nickel. These techniques will also be generalized to titanium and other metals.

Micro Fabrication of Patterned Sm2O3-doped CeO2 Electrodes on an Yttria-Stabilized Zirconia Electrolyte. CASEY STRATTON (Washington State University Pullman, WA 99163) OLGA MARINA (Pacific Northwest National Laboratory, Richland, WA, 99352)

Yttria-Stabilized Zirconia ( YSZ ) electrolyte disks with patterned Samaria-Doped Ceria (SDC) electrodes were fabricated using microphotolithography. The pattern of the electrodes had variable triple phase boundary (place where the electrode, electrolyte and gas meet). A photosensitive polymer layer was deposited on the electrolyte in a pattern negative to a desired electrode pattern, heat treated, and exposed with high intensity ultra-violet (UV) light. After that the layer was developed. SDC was deposited using direct current sputtering technique. Annealling time and temperature, polymer thickness, UV exposure time, and developing time were varied to produce a highly defined pattern. Polymer and excess of SDC that was not in direct contact with electrolyte was washed away by acetone. The obtained patterned electrode was analyzed by optical profilometry and optical microscopy.

Nanoparticle Sensors For Biological Medicine. AMEER TILLMAN (Washington State University Pullman, WA 99163) NOVELLA BRIDGES (Pacific Northwest National Laboratory, Richland, WA, 99352)

Our work is to focus on making nanoparticles that will be used as a non -invasive method to monitor intracellular trafficking and the transfection of genes. The nanoparticles characterize gradients in oxygen tension and gene expression that occur in the biofilms. The nanoparticles are made by a few different procedures such as the Ormosil and Sol - gel pebble formation. The Ormosil formation makes silica particles which are used for gene delivery. This gene delivery can deliver antibiotics or any of the other medicines that could help to kill these biofilms, once something is found that can kill them these will be really useful. These nanoparticles also determine where and how much oxygen there is in the biolfilms. This can show you how bacteria are respiring and functioning and allows you to optimize conditions so you can, for example, prevent corrosion, enhance bioremediation, or enhance chemical production.

Quality Control of Material Thickness Using Ultrasonic Scanning. BENJAMIN JOHNSON (University of Washington Seattle, WA 98195) MORRIS S. GOOD (Pacific Northwest National Laboratory, Richland, WA, 99352)

High precision characterization techniques are needed to assure quality control. In industrial settings, quality control often needs to happen at production rates. The current quality control procedure exchanges chemicals to change the index of refraction for an optical test. We proposed acoustic microscopy as a feasible high speed inspection measurement method as well as to eliminate a chemical waste stream from processes such as chemical baths. Using time of flight measurements both to the surface and through materials, it is possible to quantify thickness as well as shape parameters. To demonstrate that acoustic microscopy was a viable method, we simulated data produced by the current inspection method. With the time of flight and temperature of the water medium measured, shape and thickness could be calculated. Data was acquired at predetermined increments in order to reproduce current visual results and processed using Microsoft Excel to construct a visualization of the sample. A proof of concept test was conducted where the sample was normally scanned. This procedure proved very easy to compare thickness at all points and was consistent between repeat runs of the same specimen. Corroboration by another measurement technique is needed to evaluate performance; however, data quality was high and confidence exists that the technique will be proved successful in future work. Assuming this is performed successfully, an automated system is invisioned that could acquire all measurements almost instantaneously from multiple transducers as samples pass by a sensor. This would provide fast and reliable quality assurance, eliminate the element of human error or inconsistency, and provide an objective quantitative evaluation. Furthermore, this would save time, the cost of chemicals used by the current method, and thereby prevent a waste stream.

Rhenium Penetration in a Castable Refractory Block. BRONNIE TINSLEY (Central Washington University Ellensburg, WA 98926) MICHAEL SCHWEIGER (Pacific Northwest National Laboratory, Richland, WA, 99352)

Technetium is a radioactive element that results as a by-product from the production of nuclear weapons. Unfortunately, technetium has proven to be difficult to contain and efforts are underway to get it cleaned up. A method called bulk vitrification is currently under development that will allow technetium to be stored in large blocks of glass. The base component that makes up the glass is the desert soil found on the Hanford Reservation in Eastern Washington. Powerful electrical currents are used to heat the soil until it melts into glass in a process called vitrification. The glass melt process is contained in a block of heat resistant material called a refractory. During the melt process, the refractory block can be exposed to technetium and if it is porous enough, some of the technetium can become trapped in the refractory rather than the glass. Rhenium is an element that behaves similarly to technetium chemically but is not radioactive, and therefore is used as a surrogate for technetium in laboratory testing. In order to understand the penetration of rhenium in the refractory pores, a refractory sample was ground to dust in thin layers and the resulting dust analyzed by Inductively-Coupled Plasma Mass Spectroscopy (ICPMS) to determine the amount of rhenium each dust sample contained. The results from ICPMS showed that the distribution of rhenium in the refractory was somewhat uniform over the length of the refractory that was tested.

Sputter Rate Variations in Porous low-k dielectric Thin Films Exposed to Isopropanol Using the Auger Electron Spectrometer and the X-ray Photoelectron Spectroscopy. BRIAN PULTZ (San Joaquin Delta College Stocktion, CA 95207) SCOTT LEA (Pacific Northwest National Laboratory, Richland, WA, 99352)

Porous nanomaterials exhibit different sputtering properties than their dense counterparts upon ion beam exposure. Previous experiments have show that there are some increases in the sputter rate after the low-k dielectric (LKD) films have been exposed to isopropyl alcohol (IPA). This work is intended to sort out some of the reasons for the observed sputter rate differences after these films have been exposed to IPA. These experiments were carried out using both x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) using samples from the same wafer. For each spectrometer, four samples were used: a control that had not been exposed to IPA, a sample that was analyzed within 15 minutes of exposure to IPA, a sample that was analyzed 72 hours after exposure to IPA, and a sample that was analyzed after exposure to IPA and placed in vacuum for 72 hours. The results showed that the samples that had been exposed to the IPA have a lower sputter rate (greater sputter time) than the untreated samples. This was true for both the XPS and the AES analysis. Analysis of the samples 72 hours after IPA exposure showed a partial recovery of the initial sputter rate. This recovery was more pronounced for the sample that had been placed in vacuum for 72 hours prior to analysis. These results suggest that the added mass in the films due to the presence of IPA accounts for the decrease in sputter rate observed in previous experiments.

Stabilization of Arsenic-Bearing Residuals in Polymeric Matrices. SAVANNAH BURNSIDE (University of Arizona Tucson, AZ 85721) WENDELL ELA (Pacific Northwest National Laboratory, Richland, WA, 99352)

The USEPA's new standard for arsenic in drinking water (10 µg/L) has motivated research to safely and effectively dispose of arsenic-bearing solid residuals (ABSR) produced in water purification. This research investigates the use of polymeric matrices to encapsulate three different sorbents commonly used in the water industry to remove arsenic. Arsenic containing granular ferric oxy/hydroxide and ferric hydroxide amended alumina residuals were encapsulated in rubber-epoxy composite matrices using an aqueous-based, environmentally benign, manufacturing flowsheet. Arsenic leaching of encapsulated and unencapsulated residuals was evaluated using the standard Toxicity Characteristic Leaching Procedure (TCLP) and the more aggressive California Waste Extraction Test (CA-WET). The structure and composition of the resulting polymeric waste forms were analyzed using Scanning Electron Microscopy (SEM). Arsenic, iron and aluminum concentrations were evaluated using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The results showed that waste forms of the polymer encapsulated ABSR crushed for testing retain good leaching resistance, with arsenic levels typically 10 times lower than the unencapsulated ABSR and below the federal Toxicity Characteristics (TC) standard of 5 mg/L. When compared with conventional cement matrices containing the same ABSR, the polymeric matrices encapsulated 4 times more waste (loading levels in excess of 60 wt%) and leached arsenic at levels 1-2 orders of magnitude lower than cement.

The effect of nickel oxide on the thermal properties of an alkaline earth silicate sealing glass for planar solid oxide fuel cells. ROBERT GOW (Montana Tech Butte, MT 59701) YEONG-SHYUNG CHOU (Pacific Northwest National Laboratory, Richland, WA, 99352)

Current research on planar solid-oxide fuel cells (SOFCs) has shown them to be an efficient, environmentally friendly source of energy. One of the many remaining barriers to seeing a commercially viable SOFC has been the sealant. The sealant must prevent the direct mixing of fuel and air, be stable it oxidizing and reducing conditions, and most importantly it has to survive hundreds to thousands of thermal cycles during routine operations. For the glass or glass-ceramics approach, the sealant is required to have a closely-matched coefficient of thermal expansion (CTE) to that of the SOFC components; otherwise the seal would fracture and cause the total failure of the stack. Current glass seal developments have focused on alkaline-earth based aluminosilicate glasses. One problem was the decrease of CTE during aging. A possible solution was proposed by adding a stable phase element with a high CTE. In this study, we selected nickel oxide as the high CTE phase in a SrO-CaO silicate glass. Two approaches were used to incorporate NiO (up to 15%) into the glass. One was the melting glass approach, and the other was a composite approach. Both thermal and mechanical properties were characterized. The results of dilatometry showed a decreasing CTE with increasing NiO content for the melting glass approach, whereas opposite results were observed for the composite approach. The difference was discussed with x-ray diffraction analysis. The 10 volume percent NiO in the composite approach was used for sealing tests. A hermetic seal was found and the microstructure was characterized with electron microscopy.