U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 3651 - 3675 of 74068

Structure and Crystal Chemistry of M 0.5 Ta 0.5 B (M = Ti, Zr, and Hf)

October 12, 2021
Author(s)
I Talmy, J Zaykoski, J A. Kudak, Winnie Wong-Ng
During the development of refractory composites (cermets) combining MB2 (M=Ti, Zr, or Hf) ceramics and Ta metal, three new phases of compositions M0.5Ta0.5B were discovered. Preliminary determination of lattice parameters using x-ray powder diffraction

Structure and Reactivity of the Hydrated Hematite (0001) Surface

October 12, 2021
Author(s)
T P. Trainor, Anne M. Chaka, P J. Eng, M Newville, G A. Waychunas, J G. Catalano, G E. Brown
Hematite (alpha-Fe 2 O 3 ) is significantly more reactive to water and metal ions than its isostructure corundum (alpha-Al 2 O 3u) under environmental conditions. However, the reason for this difference is not understood. Using crystal truncation rod

Study of Isochoric Specific Heat Capacity Measurements for Liquid Isobutane

October 12, 2021
Author(s)
Hiroyuki Miyamoto, Hiroshi Kitajima, Noboru Kagawa, Joe W. Magee, Seizo Tsuruno, Koichi Watanabe
Isobutane is one of the most promising alternative refrigerants because of its zero ODP and negligible GWP. It can be used not only as a pure component but also as a component of binary or ternary mixture refrigerants. To design and evaluate cycle

Study of Photodegradation of Epoxy Polymer by Using Slow Positron Annihilation Spectroscopy

October 12, 2021
Author(s)
R Zhang, Xiaohong Gu, H Chen, J Zhang, Y Li, Tinh Nguyen, T C. Sandreczki, Y C. Jean
Slow positron annihilation spectroscopy (SPAS) has been used to study the early stage of epoxy photodegradation. Spin-coated samples of a crosslinked epoxy were prepared by stoichiometrically mixing a diglycidyl ether of bisphenol A epoxy resin with 1,3

Subsolidus Phase Relationships in the AO-AI 2 O 3 -Nb 2 O 5 (A=Ca, Sr) Systems

October 12, 2021
Author(s)
Julia Y. Chan, Wilma Feb-Ayala, J. M. Loezos, L D. Rotter, Lyle E. Levine, Richard G. Geyer
Dielectric ceramics for wireless communications exhibiting modest permittivity, high quality factor (Q), and near-zero temperature coefficient are needed for high-frequency, high power applications. Efforts are in progress to replace Ta 2O 5-based ceramics

Surface Analytical Kinetic Studies of Noise-Generating Electron Transfer Processes: In Vivo Sensing Properties of Nanoengineered Organic Cardiac Pacing Electrodes in Living Heart

October 12, 2021
Author(s)
H A. Chou, P DaeGynn, David J. Vanderah, M Ovadia
Novel organic cardiac electrode candidates enhanced by self-assembled monolayers (SAMs) are examined by varying rate cyclic voltammogram and impedance spectroscopy with hexacoordinated [Fe(CN)6]-3 as the probe for their susceptibility to Faradaic current

Surface Energy Anisotropy of SrTiO 3 at 1400 C in Air

October 12, 2021
Author(s)
T Sano, D M. Saylor, G S. Rohrer
Geometric and crystallographic measurements of grain boundary thermal grooves and surface faceting behavior as a function of orientation have been used to determine the surface energy anisotropy of SrTiO 3 at 1400 C in air. Under these conditions, thermal

Surface Morphology Dependent Magnetic Thin Film Growth: Fe on GaN(0001)

October 12, 2021
Author(s)
P Ryan, R A. Rosenberg, D J. Keavney, J W. Freeland, Joseph Woicik
Iron deposition on ordered and disordered GaN (0001) surfaces result in dramatically different magnetic over-layer characteristics. On the ordered surface, nitrogen rapidly desorbs upon Fe deposition and a magnetically disordered film is produced

Surface Treatment of Mercury Free Alloys

October 12, 2021
Author(s)
S B. Geiger, D Gurbatov, M P. Dariel, F Eichmiller, R Liberman, M Ratzker
Finishing and polishing methods were examined for two metallic direct restorative materials being proposed as possible alternatives to amalgam, namely a gallium alloy and a consolidated silver alloy. The polished surfaces were compared to a conventional

Synchrotron Based Surface Science to Probe Polymeric Interfacial Regions

October 12, 2021
Author(s)
Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, Daniel A. Fischer
Synchrotron based X-ray absorption spectroscopy was utilized to probe the chemistry and structure of polymers in interfacial regions, including the interfacial regions, including the interfacial composition of filled epoxy composites, and the surface

Synthesis and Characterization of Siloxy-Containing Imidazolium Ionic Liquids

October 12, 2021
Author(s)
Paul A. Wheeler, Jeffrey W. Gilman, L J. Mathias
A novel family of siloxy-containing imidazolium ionic liquids was synthesized and their thermal and decomposition properties studied. Three of the four compounds exhibited an unexpectedly low decomposition temperature of ca. 200 C that appears to be due to

Synthesis of Imidazolium Salts and Their Application in Epoxy Montmorillonite Nanocomposites

October 12, 2021
Author(s)
Joseph Langat, S Bellayer, P Hudrlik, A Hudrlik, P H. Maupin, Jeffrey W. Gilman, D T. Raghavan
Considerable research has been conducted in improving the performance characteristics of nanocomposites, however, relatively few attempts have been made to address the thermal stability of nanocomposite. An attempt is being made to improve the thermal

Synthesis, structure, electronic and thermal properties of sphalerite CuZn2InS4

October 12, 2021
Author(s)
Oluwagbemiga P. Ojo, Wilarachchige D. C. B. Gunatilleke, Hagen Poddig, Hsin Wang, Joshua B. Martin, Dylan J. Kirsch, George S. Nolas
Quaternary chalcogenides continue to be of interest due to the variety of physical properties they possess, as well as their potential for different applications of interest. Investigations on materials with the sphalerite crystal structure have only

Systematic Study of Cancellation of Errors in the Benzene Dimer Interaction Energy

October 12, 2021
Author(s)
Ines Gonzalez, Stephen L. Garrison, M Marquez, Carlos A. Gonzalez, E C. Lim
We present a broadly applicable method or diagnostic for the appropriateness of the counterpoise correction and illustrate its value via calculations on the benzene dimer. The results also explain the fortuitous cancellation of errors that led to good
Displaying 3651 - 3675 of 74068