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in subjects: "Microanalysis"

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Ion beam characterization of multi-layer dielectric reflectors

Energetic ion beams were used to characterize multilayer dielectric reflectors. Alpha-particle beams with beam spot sizes between 10 microns and a few millimeters were scattered from reflectors consisting of 32-layer SiO/sub 2//HfO/sub 2/ and 38-layer MgF/sub 2//ThF/sub 4/. The RBS spectra reveal the nature of the laser damage processes by providing information on diffusion, mixing, and loss of material in the coatings. The particle-induced x-ray emission (PIXE) technique gave complimentary res… more

Date: January 1, 1985

Creator: Beery, J. G.; Hollander, M. G.; Maggiore, C. J.; Redondo, A.; Westervelt, R. T. & Taylor, T. N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Determination of B and Li in nuclear materials by secondary-ion mass spectrometry

Secondary ion mass spectrometry (SIMS) was used to perform mass and isotopic analysis for B and Li in samples that are not readily amenable to more conventional mass spectrometric techniques (e.g., surface ionization, electron impact, etc.). In this paper three specific applications of SIMS analysis to nuclear materials are discussed: first, the quantitative determination of B and its isotopic composition in borosilicate glasses; second, the determination of the isotopic composition of B and Li… more

Date: January 1, 1981

Creator: Eby, R.E. & Christie, W.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of flyash surface phenomena and the application of surface analysis technology. Summary report: Phase I. [44 elements; 86 references]

The factors governing the formation of flyash surfaces during and following coal combustion are reviewed. The competing chemical and physical processes during the evolution of inorganic material in coal during combustion into flyash are described with respect to various surface segregation processes. Two mechanisms leading to surface enrichment are volatilization-condensation processes and diffusion processes within individual flyash particles. The experimental evidence for each of these proces… more

Date: June 1, 1981

Creator: Smith, R. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Surface analysis of titanium coated silicone rubber biological implants

A wide variety of materials are used today in the fabrication of biomedical implants. Various plastics, ceramics, metals, and composites are found in dozens of applications as biomaterials. The biological interactions between the implant surfaces and the proteins and cells of the body sometimes cause problems such as inflammation, thrombosis, and encapsulation. Coating the implants with a biocompatible material such as titanium could alleviate these problems. In an effort to improve the biologi… more

Date: January 1, 1987

Creator: Farr, J.D. & Hutchinson, W.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Basalt Alteration and Basalt-Waste Interaction in the Pasco Basin of Washington State. Final Report

A study was conducted to determine the nature of the minerals which coat vesicle and fracture surfaces in the Grande Ronde Basalt Formation, simulate the mass transfer which led to their precipitation, and predict the mass transfer associated with the dissolution of spent unreprocessed fuel (SURF). Scanning electron microscopy (SEM), petrographic, x-ray diffraction (XRD), and electron microprobe (EMP) analyses have been made on a series of samples taken from 1100 ft (335.3 m) of core from core … more

Date: September 1, 1978

Creator: Benson, L. V.; Carnahan, C. L.; Apps, J. A.; Mouton, C. A.; Corrigan, D. J.; Frisch, C. J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Ion microprobe mass spectrometry using sputtering atomization and resonance ionization

Resonance ionization mass spectrometry (RIMS) has recently been developed into a useful technique for isotope ratio measurements. Studies performed in our laboratory (1-6) have been reported for a variety of elements using thermal vaporization sources to produce the atom reservoir for laser-induced resonance ionization. A commercial ion microprobe mass analyzer (IMMA) has been interfaced with a tunable pulsed dye laser for carrying out resonance ionization mass spectrometry of sputtered atoms. … more

Date: January 1, 1985

Creator: Donohue, D. L.; Christie, W. H. & Goeringer, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Positron microanalysis with high intensity beams

One of the more common applications for a high intensity slow positron facility will be microanalysis of solid materials. In the first section of this paper some examples are given of procedures that can be developed. Since most of the attendees of this workshop are experts in positron spectroscopy, comprehensive descriptions will be omitted. With the exception of positron emission microscopy, most of the procedures will be based on those already in common use with broad beams. The utility of t… more

Date: January 1, 1990

Creator: Hulett, L. D. Jr. & Donohue, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

In situ secondary ion mass spectrometry analysis

The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it… more

Date: January 1, 1993

Creator: Groenewold, G. S.; Applehans, A. D.; Ingram, J. C.; Delmore, J. E. & Dahl, D. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Determination of pseudogap state density and carrier mobility in rf sputtered amorphous silicon. Final technical report, July 1, 1979-June 30, 1980

The first objective is to determine whether field effect could be observed in samples of sputtered hydrogenated amorphous silicon, and, if it could, to compare the pseudogap density of states determined therefrom with estimates made by other methods of investigation. The second is to determine the drift mobility of excess carriers in these materials by time-of-flight, and to interpret its magnitude and temperature dependence in terms of current theories of transport in disordered semiconductors… more

Date: September 1, 1980

Creator: Paul, William; Anderson, David A. & Weisfield, Richard L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Data acquisition with a nuclear microprobe

Spatially resolved information from the near surfaces of materials can be obtained with a nuclear microprobe. The spatial resolution is determined by the optics of the instrument and radiation damage in the specimen. Two- and three-dimensional maps of elemental concentration may be obtained from the near surfaces of materials. Data are acquired by repeated scans of a constantly moving beam over the region of interest or by counting for a preset integrated charge at each specimen location.

Date: January 1, 1980

Creator: Maggiore, C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

X-ray microanalysis using an HVEM

The interfacing of an energy dispersive x-ray spectrometer (EDS) to an HVEM has been suggested during the last few years as a means by which the mass sensitivity of x-ray analysis in a TEM can be increased. The prediction of higher sensitivity is related to the anisotropic distribution of continuum radiation generated by high energy electron excitation of a thin sample. Depending on the geometry, this can result in an increase in the measured peak-to-background (P/B) ratio of a characteristic l… more

Date: January 1, 1978

Creator: Zaluzec, N.J.; Kenik, E.A. & Bentley, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Controlled sample program publication No. 1: characterization of rock samples.

A description is presented of the methodology used and the geologic parameters measured on several rocks which are being used in round-robin laboratory and nuclide adsorption methodology experiments. Presently investigators from various laboratories are determining nuclide distribution coefficients utilizing numerous experimental techniques. Unfortunately, it appears that often the resultant data are dependent not only on the type of groundwater and rock utilized, but also on the experimentor o… more

Date: October 1978

Creator: Ames, L. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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9519 biotite granodiorite reacted in a temperature gradient

A biotite granodiorite from the Fenton Hill Hot Dry Rock (HDR) geothermal system was reacted in a controlled temperature gradient with initially distilled water for 60d. Polished rock prisms were located in the gradient at 72, 119, 161, 209, 270, and 310/sup 0/C. Scanning electron microscope and microprobe analyses show the appearance of secondary phases: Ca-montmorillonite at 72/sup 0/C and 119/sup 0/C; zeolite, either stilbite or heulandite, at 161/sup 0/C; and another zeolite, thomsonite, at… more

Date: October 1, 1980

Creator: Charles, R. W. & Bayhurst, Gregory K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Uranium-contaminated soils: Ultramicrotomy and electron beam analysis

Uranium-contaminated soils from the U.S. Department of Energy (DOE) Fernald Site, Ohio, have been examined by a combination of scanning electron microscopy with backscattered electron imaging (SEM/BSE) and analytical electron microscopy (AEM). The inhomogeneous distribution of particulate uranium phases in the soil required the development of a method for using ultramicrotomy to prepare transmission electron microscopy (TEM) thin sections of the SEM mounts. A water-miscible resin was selected t… more

Date: February 1, 1994

Creator: Buck, E. C.; Dietz, N. L.; Bates, J. K. & Cunnane, J. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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[Energy Related Studies Utilizing Microline Thermochronology]. Progress Report, 1990--1991

In our first year of the current funding cycle, we have investigated three interrelated aspects of K-feldspar thermochronology; (1) the Ar diffusion properties and microstructures of K-feldspars, (2) the thermal evolution of the Valles Caldera and (3) the continued development of microanalysis. Results of TEM and light microscopy on heated and unheated samples of MH-10 K-feldspar reveal three classes of substructure are present: (1) cross hatched extinction is common and there is almost no albi… more

Date: December 31, 1991

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Continuum fluorescence of Cu in NbTi/Cu composite wires

Continuum fluorescence across interfaces separating regions of differing composition is difficult to calculate. This paper illustrates a case of continuum fluorescence in analysis of superconducting NbTi/Cu composite wire which could lead to erroneous compositions due to Cu fluorescence by continuum x rays generated in an NbTi alloy. An approximate treatment of the continuum fluorescence is presented. 3 figs, 4 refs.

Date: April 1, 1994

Creator: Hlava, P. F.; Michael, J. R.; Nelson, G. C. & Headley, T. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of Z-contrast imaging to obtain column-by-column spectroscopic analysis of materials

Z-contrast imaging has been shown to be an effective method for obtaining a high-resolution image from a scanning transmission electron microscope (STEM). The incoherent nature of the high-angle scattering makes image interpretation straightforward and intuitive with the resolution limited only by the 2.2 {Angstrom} electron probe. The optimum experimental conditions for Z-contrast imaging also coincide with those used for analytical microscopy, enabling microanalysis to be performed with the s… more

Date: January 1, 1993

Creator: Browning, N. D. & Pennycook, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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PIXE microanalysis of Fe-sulfides: Comparison of eastern and western coals

Several of the toxic-heavy metals listed for consideration in the Clean Air Acts Amendments of 1990 are strongly concentrated in Fe-sulfides, particularly Ni, As, Se, Hg, and Pb. This finding suggests that significant mitigation of utility emissions of these metals will result from pre-combustion beneficiation that removes Fe-sulfides from feed coals. The heterogeneities of individual metals in single channel samples suggests that in some seams only certain stratigraphic layers in a seam are li… more

Date: July 1, 1993

Creator: Hickmott, D. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Detection of single molecules in microspheres

We have investigated the use of micron-sized liquid droplets as sample medium to detect single fluorescent molecules in solution. The use of microdroplets (5--15 {mu}m diameter) offers several powerful advantages over single-molecule detection schemes involving measurements on bulk liquids where the probe volume is defined by the laser beam. In addition, cavity-quantum electrodynamical (QED) effects have been observed which influence both spontaneous emission rates and fluorescence yields of dy… more

Date: July 1, 1993

Creator: Barnes, M. D.; Whitten, W. B.; Ramsey, J. M.; Ng, K. C. & Arnold, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A High-Throughput Microenvironment for Single-Cell Operations

This project was conducted as a feasibility study, in preparation for including this work in the forthcoming ''Instrumented Cell'' (IC) Strategic Initiative. The goal of the IC is to study individual cells; the goal of this feasibility study was to determine the best method for isolating large numbers of individual cells in a way that facilitates various types of environmental changes and intracellular measurements. We have the capability to do this with one cell, and sought to expand the numbe… more

Date: January 7, 2003

Creator: Christian, A. T.; Buckley, P. & Miles, R. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Probing interface structure and bonding at atomic resolution by STEM

Advantage of STEM is that no model structures are required to interpret the images to first order, so that unexpected interfacial phenomena will be immediately apparent, such as in CoSi{sub 2}/Si(100) interface made by Co implantation/annealing. By depositing two monolayer Ge marker layers during growth of Si{sub 0. 5}Ge{sub 0.5} alloy layer, a misfit dislocation was found to nucleate to relieve the strain. Hole concentration profiles can be measured in YBCO superconductor, using the pre-edge o… more

Date: June 1, 1993

Creator: Pennycook, S. J.; Browning, N. D.; Jesson, D. E. & Chisholm, M. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

LORENTZ PHASE IMAGING AND IN-SITU LORENTZ MICROSCOPY OF PATTERNED CO-ARRAYS.

Understanding magnetic structures and properties of patterned and ordinary magnetic films at nanometer length-scale is the area of immense technological and fundamental scientific importance. The key feature to such success is the ability to achieve visual quantitative information on domain configurations with a maximum ''magnetic'' resolution. Several methods have been developed to meet these demands (Kerr and Faraday effects, differential phase contrast microscopy, magnetic force microscopy, … more

Date: August 3, 2003

Creator: VOLKOV,V. V. ZHU,Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Preliminary studies of the alteration of a granite by an artificial hydrothermal system

Solution channels in quartz, microcline, and plagioclase of a granite were produced by exposure of the rock to an artificial hydrothermal system. Electron microprobe analyses, beam-scanning photographs, and element profiles show that the mineral grains are homogeneous and unaltered within a few micrometers of the channels. The channels, which are 3 to 7 ..mu.. in diameter, appear to have formed by removal of material in solution. In the sample material, no new minerals produced by alteration or… more

Date: February 1, 1977

Creator: Ehrenberg, S. N.; Perkins, P. C. & Balagna, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Ion backscattering studies of Synthoil catalyst materials. [2 MeV /sup 4/He/sup +/ ions]

Energetic ion backscattering has been used to analyze new and used CoMo catalyst pellets in support of the SYNTHOIL Process catalyst deactivation study. These analyses enabled the first absolute quantitative determinations of atomic composition and compositional gradients within the pellets. In cases where they can be compared, the backscattering data agree with data from parallel analysis programs using the electron microprobe and Auger spectroscopy. Enrichment of Mo and Ca in the outer 2 ..mu… more

Date: May 1, 1977

Creator: Borders, J. A. & Peterson, G. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department