The Magnetic Correlations and Fluctuations in the Geometrically Frustrated Antiferromagnetic Spinel CdCr2O4: An Experiment Using the SPINS Triple-Axis Spectrometer Summer School on Methods and Applications of Neutron Spectroscopy NIST Center for Neutron Research

The Magnetic Phase Transition and Spin Fluctuations in the Geometrically Frustrated Antiferromagnetic Spinel CdCr2O4: An Experiment Using the SPINS Triple-Axis Spectrometer

CdCr2O4 is a magnetic compound that crystallizes into what is known as a cubic spinel structure, and the magnetic properties stem from the Cr3+ ions, which form a network of corner-sharing tetrahedra. Despite the presence of relatively strong antiferromagnetic, nearest-neighbor interactions between these ions, the peculiar spatial arrangement of the Cr atoms within the spinel structure actually...

ابررساناهای دمای بالا- با دید نوترونها

  Neutron scattering is proved to be a vital probe in unveiling the magnetic properties of high temperature superconductors (HTSC). Detailed information about the energy and momentum dependence of the magnetic dynamics of HTSC have been obtained directly by this technique. Over the past decade by improving the crystal growth methods, large and high quality single crystals of HTSC, which are ess...

Quantum Rotations in Methyl Iodide (CH3I) An experimental investigation using the High-Flux Backscattering Spectrometer and Filter Analyzer Neutron Spectrometer NIST Center for Neutron Research Summer School on Methods and Applications of Neutron Spectroscopy June 25-29, 2007 HFBS Team

We will use inelastic neutron scattering to examine the quantum rotational dynamics of methyl iodide (also known as iodomethane, CH3I), a textbook example of a symmetric quantum top. The goal of this hands-on measurement is to gain an understanding and appreciation of the backscattering and filter analyzer measurement techniques, get practical experience in obtaining inelastic neutron scatterin...

Spin-phonon coupling in antiferromagnetic chromium spinels

The temperature dependence of eigenfrequencies and intensities of the IR active modes has been investigated for the antiferromagnetic chromium spinel compounds CdCr2O4, ZnCr2O4, ZnCr2S4, ZnCr2Se4, and HgCr2S4 by IR spectroscopy for temperatures from 5 K to 300 K. At the transition into the magnetically ordered phases, and driven by spin-phonon coupling, most compounds reveal significant splitti...

Magnetic Structure of Iron Oxide Nanoparticles Using SANS Summer School on Small Angle Neutron Scattering and Neutron Reflectometry NIST Center for Neutron Research