RSI Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

Feb 2013

Volume 84, Issue 2, Articles (02xxxx)

Issue Cover Spotlight Figure

Rev. Sci. Instrum. 84, 021101 (2013); http://dx.doi.org/10.1063/1.4789314 (14 pages)

Alexey Goncharov

Typical permanent magnet electrostatic plasma lens, characteristically about 15 cm long and 10 cm inner diameter. The magnets are shown in black between grey spacers. A set of cylindrical ring electrodes are located within the magnetic field region, with field lines connecting ring electrode pairs symmetrically about the lens midplane.

Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds
back to top Condensed Matter; Materials

Synchrotron radiation-based far-infrared spectroscopic ellipsometer with full Mueller-matrix capability

T. N. Stanislavchuk, T. D. Kang, P. D. Rogers, E. C. Standard, R. Basistyy, A. M. Kotelyanskii, G. Nita, T. Zhou, G. L. Carr, M. Kotelyanskii, and A. A. Sirenko

Rev. Sci. Instrum. 84, 023901 (2013); http://dx.doi.org/10.1063/1.4789495 (15 pages)

Online Publication Date: 5 February 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We developed far-IR spectroscopic ellipsometer at the U4IR beamline of the National Synchrotron Light Source in Brookhaven National Laboratory. This ellipsometer is able to measure both, rotating analyzer and full-Mueller matrix spectra using rotating retarders, and wire-grid linear polarizers. We utilize exceptional brightness of synchrotron radiation in the broad spectral range between about 20 and 4000 cm−1. Fourier-transform infrared (FT-IR) spectrometer is used for multi-wavelength data acquisition. The sample stage has temperature variation between 4.2 and 450 K, wide range of θ–2θ angular rotation, χ tilt angle adjustment, and X-Y-Z translation. A LabVIEW-based software controls the motors, sample temperature, and FT-IR spectrometer and also allows to run fully automated experiments with pre-programmed measurement schedules. Data analysis is based on Berreman's 4 × 4 propagation matrix formalism to calculate the Mueller matrix parameters of anisotropic samples with magnetic permeability μ ≠ 1. A nonlinear regression of the rotating analyzer ellipsometry and/or Mueller matrix (MM) spectra, which are usually acquired at variable angles of incidence and sample crystallographic orientations, allows extraction of dielectric constant and magnetic permeability tensors for bulk and thin-film samples. Applications of this ellipsometer setup for multiferroic and ferrimagnetic materials with μ ≠ 1 are illustrated with experimental results and simulations for TbMnO3 and Dy3Fe5O12 single crystals. We demonstrate how magnetic and electric dipoles, such as magnons and phonons, can be distinguished from a single MM measurement without adducing any modeling arguments. The parameters of magnetoelectric components of electromagnon excitations are determined using MM spectra of TbMnO3.
Show PACS
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
07.60.Fs Polarimeters and ellipsometers
41.60.Ap Synchrotron radiation
42.79.Ci Filters, zone plates, and polarizers

Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

C. L. Morris, M. Bourke, D. D. Byler, C. F. Chen, G. Hogan, J. F. Hunter, K. Kwiatkowski, F. G. Mariam, K. J. McClellan, F. Merrill, D. J. Morley, and A. Saunders

Rev. Sci. Instrum. 84, 023902 (2013); http://dx.doi.org/10.1063/1.4789947 (7 pages)

Online Publication Date: 11 February 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.
Show PACS
07.85.Fv X- and γ-ray sources, mirrors, gratings, and detectors
42.79.Ag Apertures, collimators

Practical guide for validated memristance measurements

Nan Du, Yao Shuai, Wenbo Luo, Christian Mayr, René Schüffny, Oliver G. Schmidt, and Heidemarie Schmidt

Rev. Sci. Instrum. 84, 023903 (2013); http://dx.doi.org/10.1063/1.4775718 (7 pages)

Online Publication Date: 13 February 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Chua [IEEE Trans. Circuit Theory 18, 507–519 (1971)10.1109/TCT.1971.1083337] predicted rather simple charge-flux curves for active and passive memristors (short for memory resistors) and presented active memristor circuit realizations already in the 1970 s. The first passive memristor has been presented in 2008 [D. B. Strukov, G. S. Snider, and D. R. Williams, Nature (London) 453, 80–83 (2008)10.1038/nature06932]. Typically, memristors are traced in complicated hysteretic current-voltage curves. Therefore, the true essence of many new memristive devices has not been discovered so far. Here, we give a practical guide on how to use normalized charge-flux curves for the prediction of hysteretic current-voltage characteristics of memristors. In the case of memristive BiFeO3 thin film capacitor structures, the normalized charge-flux curves superimpose for different numbers of measurement points Ns and a different measurement time per measurement point Ts. Such normalized charge-flux curves can be used for the prediction of current-voltage characteristics for input signals with arbitrarily chosen Ns and Ts.
Show PACS
84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)
06.30.Ft Time and frequency
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)
84.32.Tt Capacitors

Translational diffusion of probe molecules under high pressure: A study by fluorescence recovery after photobleaching technique

Marco Bonetti and Michel Roger

Rev. Sci. Instrum. 84, 023904 (2013); http://dx.doi.org/10.1063/1.4790567 (6 pages)

Online Publication Date: 14 February 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present fluorescence recovery measurements after photobleaching performed under high pressure in liquids that fill square-section fused silica micro-capillaries. These micro-capillaries withstand pressure up to 2500 bar for a wall thickness of about 140 μm and fit easily on the microscope stage. This technique allows the translational diffusion coefficient of fluorescent molecules in liquids to be measured as a function of pressure. When the liquid sample is far from its glass transition the translational diffusive coefficient is in agreement with the Stokes-Einstein equation. As the glass transition is approached by further increasing the pressure, decoupling of the measured diffusion coefficient from the Stokes-Einstein relation is observed. These are the first measurements that combine the fluorescence recovery technique and high hydrostatic pressures. This experimental setup can also be used either with diamond or sapphire anvil cells in order to span a larger pressure range.
Show PACS
42.50.Gy Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption
42.65.-k Nonlinear optics
78.55.-m Photoluminescence, properties and materials
07.35.+k High-pressure apparatus; shock tubes; diamond anvil cells

Demonstration of glass transition temperature shift in thin supported polystyrene films by internal reference method

Mikhail Yu. Efremov, Christopher Thode, and Paul F. Nealey

Rev. Sci. Instrum. 84, 023905 (2013); http://dx.doi.org/10.1063/1.4793226 (6 pages)

Online Publication Date: 26 February 2013

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An internal reference method is used for the first time to clearly demonstrate the glass transition temperature (Tg) depression effect in 5 nm thick polystyrene films spin-cast on silicon wafers. Initially flat films exhibit depressed Tg at approximately 85 °C. Temperature-induced dewetting on hexamethyldisilazane-treated silicon substrates leads to formation of discontinuous films with average effective thickness of 15–30 nm. Dewetted films demonstrate Tg close to the bulk value (≈ 100 °C) and are used as internal references. Data both for continuous and discontinuous films are obtained in the same experimental run for the same sample, which allows direct comparison between datasets. Phase-modulated ellipsometry in vacuum is used to monitor glass transition. Both traditional linear temperature scan method and a novel temperature modulated technique have been employed in the measurements.
Show PACS
64.70.pj Polymers
07.20.Dt Thermometers
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close