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Displaying 49651 - 49675 of 74129

Interactions Between Bicrystal Josephson Junctions in a Multilayer Structure

June 1, 1999
Author(s)
H. Q. Li, Ronald H. Ono, Leila R. Vale, David A. Rudman, Sy-Hwang Liou
We have fabricated and studied a variety of devices based on stacked Yba 2Cu 3O x bicrystal Josephson junctions in a multilayer structure. The proximity of the junctions in the two layers produces a large number of effects based on interactions between the

Intercomparison of SEM, AFM, and Electrical Linewidths

June 1, 1999
Author(s)
John S. Villarrubia, Ronald G. Dixson, Samuel N. Jones, J R. Lowney, Michael T. Postek, Richard A. Allen, Michael W. Cresswell
Uncertainty in the locations of line edges dominates the uncertainty budget for high quality sub-micrometer linewidth measurements. For microscopic techniques like scanning electron microscopy (SEM) and atomic force microscopy (AFM), the image of the sharp

Internet-based Distributed Measurement and Control Applications

June 1, 1999
Author(s)
Kang B. Lee, Richard D. Schneeman
This paper describes research and development work conducted at the National Institute of Standards and Technology (NIST) on an Internet-based Distributed Measurement and Control (DMC) system. The work has resulted in applications that highlight state-of

Isochoric Heat Capacity Measurements for Binary Refrigerant Mixtures Containing Difluoromethane (R32), Pentafluoroethane (R125), 1,1,1,2-Tetrafluoroethane (R134a), and Trifluoroethane (R143a) From 200 to 345 K at Pressures ato 35 Mpa

June 1, 1999
Author(s)
Joe W. Magee
Molar heat capacities at constant volume C v were measured for binary refrigerant mixtures with an adiabatic colorimeter with gravimetric determinations of the amount of substance. Temperatures ranged from 200 to 345 K, while pressures extended up to 35

Isochoric p-rho-T and Heat Capacity Cv Measurements for Ternary Refrigerant Mixtures Containing Difluoromethane (R32), Pentafluoroethane (R125), and 1,1,1,2-Tetrafluoroethane (R134a) From 200 to 400 at Pressures to 35 MPa

June 1, 1999
Author(s)
Joe W. Magee
The p-p-T relationships and constant volume heat capacity C υ were measured fro ternary refrigerant mixtures by isochoric methods with gravimetric determinations of the amount of substance. Temperatures ranged from 200 to 400 K for p-p-T and from 203 to

Just How Perfect Can a Perfect Crystal Be?

June 1, 1999
Author(s)
R Deslattes, Ernest G. Kessler, S M. Owens, David R. Black, Albert Henins
This overview addresses certain aspects of the perfection of the current generation of commercially manufactured silicon, specifically lattice uniformity and the more complex issues of interstitials, vacancies, and chemical impurities. The application

Large Area YBa 2 Cu 3 O 7-x Bolometers on Si Substrates

June 1, 1999
Author(s)
Leila R. Vale, Ronald H. Ono, Donald G. McDonald, Robert J. Phelan
We have developed YBa 2Cu 3O 7-x (YBCO) thermometers for large-area (4 mm x 4 mm) electrical substitution bolometers. We passivated the YBCO with a thin Au layer and demonstrated a noise equivalent temperature of 4 nK Hz -1/2. We then used a resistor layer

Linux-Based Clusters at the National Institute of Standards and Technology

June 1, 1999
Author(s)
Wayne J. Salamon, Alan Mink
The Scalable Parallel Systems and Applications Group at the National Institute of Standards and Technology (NIST) has been experimenting with Linux-based clusters of computers. These clusters are used for both the running of computationally intensive

Long Term Stability of YBCO-Based Josephson Junctions

June 1, 1999
Author(s)
Leila R. Vale, Ronald H. Ono, J. Talvacchio, M. G. Forrester, B. D. Hunt, M. S. DiTorio, Ki Youl Yang, S. Yoshizumi
We report on a study of long term aging in three different types of Yba 2Cu 3O 7-x Josephson junctions. Junction aging will affect the choices made in integrating this technology with actual applications. The junction types used in this study are (a) Co

Lowering the Limit of Detection in High Spatial Resolution Electron Beam Microanalysis With the Microcalorimeter Energy Dispersive X-Ray Spectrometer

June 1, 1999
Author(s)
Dale E. Newbury, David A. Wollman, Kent D. Irwin, Gene C. Hilton, John M. Martinis
Low-beam-energy x-ray microanalysis with the field-emission-gun scanning electron microscope suffers limitations due to physical factors of x-ray generation. Instrumental limitations are imposed by the poor resolution of the conventional semiconductor

Mean-Field-Scaling in Lattice Boltzmann Fluid Mixtures

June 1, 1999
Author(s)
Nicos Martys, Jack F. Douglas
Basic equilibrium properties of Lattice Boltzmann (LB) fluid mixtures (coexistence curve, surface tension, and interfacial profile) are calculated to characterize the critical phenomena occurring in these model liquids and to establish a reduced variable

Measurement Traceability to NIST Standard Rockwell Diamond Indenters

June 1, 1999
Author(s)
Jun-Feng Song
A metrology-based Rockwell hardness scale is established by a standard machine and a standard diamond indenter. Both must be established through force and dimensional metrology with acceptably small measurement uncertainties. In 1994, NIST developed a

Measurement Uncertainity and Noise in Nanometrology

June 1, 1999
Author(s)
James E. Potzick
The measurement of feature sizes on integrated circuit photomasks and wafers is an economically important and technically challenging application of nanometrology. The displacement measuring laser heterodyne interferometer is a popular tool in such

Microleakage of a Consolidted Silver Direct Filling Material

June 1, 1999
Author(s)
F Eichmiller, Anthony A. Giuseppetti, Kathleen M. Hoffman, D R. Brajdic, V Miksch, J A. Delorey-Lytle
Microleakage of an experimental direct filling materisl comprised of a chemically precipitated silver powder that had been surface treated with a dilute acid to promote cold welding upon consolidation was evaluated. Microleakage was compared to both

Molecular Models of Water. I. Derivation and Description

June 1, 1999
Author(s)
A Wallqvist, Raymond D. Mountain
Molecular level computer simulations based on molecular dynamics and Monte Carlo methods have become widely used techniques in the study and modeling of aqueous systems. These simulations of water involve a few hundred to a few thousand water molecules at

Nanoscale Chemical Imaging With Scanning Near-Field Infrared Microscopy

June 1, 1999
Author(s)
Chris A. Michaels, Stephan J. Stranick, Lee J. Richter, Richard R. Cavanagh
The development of a near-field microscope that utilizes infrared absorption as the optical contrast mechanism will be described. This instrument couples the nanoscale spatial resolution of a scanning probe microscope with the chemical specificity of

Neutron Powder Diffraction of Carbon-Coated FeCo Alloy Nanoparticles

June 1, 1999
Author(s)
J H. Scott, K Chowdary, Z Turgut, S. A. Majetich, M E. McHenry
Neutron powder diffraction is used to study the order-disorder transformation in carbon-coated Fe xCo 1-x nanoparticles produced using a radio frequency (RF) plasma torch. The nanoparticles, nominally Fe 50Co 50, are produced from alloy powder and
Displaying 49651 - 49675 of 74129