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 401 - 425 of 1560

Imaging with modular linear arrays of cryogenic Nb microbolometers

March 17, 2008
Author(s)
Erich N. Grossman, Charles Dietlein, Jon E. Bjarnason, Mabel Ramirez, M. Leivo, J. A. Penttila, P. Helisto, A. Luukanen
We present ultrawideband imagery obtained with modular, 8-element, superconducting Nb microbolometer arrays. Conically scanned images are presented and compared with raster-scanned images obtained on the same arrays and from similar NbN arrays at VTT

Spin Transfer Precessional Dynamics in Co 60 Fe 20 B 20 Nanocontacts

March 14, 2008
Author(s)
William H. Rippard, Matthew R. Pufall, Michael L. Schneider, Kevin Garello, Stephen E. Russek
We report on the precessional dynamics in spin transfer oscillators having Co 60Fe 20B 20 free layers as a function of annealing time at 225 °C. Repeated annealing reduces the critical current I c by roughly a factor of 3 and increases the tunability of

Dependence of noise in magnetic tunnel junction sensors on annealing field and temperature

March 7, 2008
Author(s)
Stephen E. Russek, David P. Pappas, Sean Halloran, Lu Yuan, Sy-Hwang Liou, Rui Zhang
The minimum detectable field of magnetoresistive sensors is limited by their intrinsic noise. Magnetization fluctuations are one of the crucial noise sources and are related to the magnetization alignment at the antiferromagnetic – ferromagnetic interface

The Beginnings of This TRANSACTIONS

March 1, 2008
Author(s)
Dylan F. Williams, Admir Mortazawi
In July, 1951, Ben Warriner (chairman, 1952-1953) circulated a petition to begin the Microwave Theory and Techniques Society under the auspices of the Institute of Radio Engineers. Despite an initial lack of support from the IRE, the roots of the

Broadband Permittivity Measurements of Thin-Film Ferroelectrics to 40 GHz

February 25, 2008
Author(s)
Nathan D. Orloff, James C. Booth, Makoto Murakami, Ichiro Takeuchi
We demonstrate a novel experimental technique to measure the complex permittivity function of dielectric thin films over the frequency range from 100 Hz to 40 GHz. We apply this technique to determine the broadband permittivity function for ferroelectric

Hydrogenization of Zr 0.9 Ti 0.1 Cr x Fe 2-x Intermetallic Compounds: Free Electron Model for Magnetic Susceptibility and Thermoelectric Power

January 24, 2008
Author(s)
S. Niyomsoan, P. Termsuksawad, Ronald B. Goldfarb, David Olson, B. Mishra, Z Gavra, V I. Kaydanov
The magnetic susceptibility and thermoelectric power of Zr 0.9Ti 0.1Cr xFe 2-x intermetallic compounds were investigated as functions of hydrogen content. The alloys are all paramagnetic, with magnetic susceptibility and Seebeck coefficient increasing with

256-Channel Magnetic Imaging System

January 18, 2008
Author(s)
Fabio C. da Silva, Sean Halloran, Anthony B. Kos, David P. Pappas
We present the design and fabrication of a magentoresistive imaging system capable of measuring 256 channels simultaneously along linear ranges of 4 mm and 13 mm. The channels are interfaced by custom electronics and the images are displayed in real time

256-channel magnetic imaging system

January 15, 2008
Author(s)
Fabio C. Da Silva, Sean Halloran, Anthony B. Kos, David P. Pappas
We present the design and fabrication of a magnetoresistive imaging system capable of scanning 256 channels simultaneously along linear ranges of either 4 or 13 mm. High speed electronics read the channels and transfer the data to a computer that builds

Development of a thin film magnetic moment reference material

January 1, 2008
Author(s)
Robert R. Owings, Fabio C. Da Silva, David P. Pappas
This paper presents the results of an interlaboratory comparison and development of a magnetic moment reference material. The comparison was between the National Institute of Standards and Technology, magnetometer manufacturers, industrial, academic, and

Nanomechanical Mapping with Resonance Tracking Scanned Probe Microscope

November 23, 2007
Author(s)
Anthony B. Kos, Donna C. Hurley
We present a new digital-signal-processor-based resonance tracking system for scanned probe microscopy (SPM) imaging. The system was developed to enable quantitative imaging of mechanical properties with nanoscale spatial resolution at practical data

Sources of Uncertainty for Near-Field Measurements

November 11, 2007
Author(s)
Michael H. Francis, Ronald C. Wittmann
We discuss the sources of uncertainty in near-field measurements and their impact on far-field antenna parameters. The methods of estimating these uncertainties can be considered in three broad categories: theoretical estimation (analytical), computer

Delivery of Fluorescent Probes Using Iron Oxide Particles as Carriers Enables In Vivo Labeling of Migrating Neural Precursors for MRI and Optical Imaging

November 1, 2007
Author(s)
James P. Sumner, Richard Conroy, Eric Shapiro, John M. Moreland, Alan P. Koretsky
Iron oxide particles are becoming an important contrast agent for magnetic resonance imaging (MRI) cell tracking studies. Simultaneous delivery of fluorescence indicators with the particles to individual cells offers the possibility of correlating optical

Absolute Magnitude and Phase Calibrations

October 1, 2007
Author(s)
Kate Remley, Paul D. Hale, Dylan Williams
In VNA measurements, the magnitude and phase of a transmitted or reflected wave are measured relative to that of the incident wave. VNA measurements are made a single frequency at a time and each frequency component is acquired relative to the internally

Experimental determination of the inhomogeneous contribution to linewidth in Permalloy films using a time-resolved magneto-optic Kerr effect microprobe

September 12, 2007
Author(s)
Michael Schneider, Thomas Gerrits, Anthony B. Kos, Thomas J. Silva
We adapted a time-resolved magneto-optic microprobe for use with the pulsed inductive microwave magnetometer apparatus, allowing us to measure the magnetization dynamics of a thin Permalloy film at micrometer and millimeter length scales under exactly the

STANDARDS DEVELOPMENT FOR REMOTE SENSING AT MICROWAVE AND TERAHERTZ FREQUENCIES

September 7, 2007
Author(s)
James P. Randa, Eyal Gerecht, Dave K. Walker, Amanda Cox, Dazhen Gu, Lixing You, Robert L. Billinger
The Noise Project in the Electromagnetics Division of the National Institute of Standards and Technology (NIST) has proposed the development of standards for microwave brightness temperature, for use in remote-sensing applications such as satellite-based

Chip-level Security for RFID Smart Cards and Tags

September 4, 2007
Author(s)
Dylan Williams, Kate Remley
This report on RFID chip-level security is written to help both technical and non-technical audiences navigate the complex chip-level security features of RFID smart cards and tags, and make intelligent security choices. The report explores both attacks
Displaying 401 - 425 of 1560