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Displaying 1 - 12 of 12

Cesium Substitution Disrupts Concerted Cation Dynamics in Formamidinium Hybrid Perovskites

July 28, 2020
Author(s)
Eve M. Mozur, Michael A. Hope, Julia C. Trowbridge, David M. Halat, Luke L. Daemen, Annalise E. Maughan, Timothy R Prisk, Clare P. Grey, James R. Neilson
While hybrid perovskites show great promise for photovoltaic applications, several of the most technologically relevant hybrid perovskites degrade rapidly when exposed to water, oxygen, or infrared and ultraviolet radiation. Empirical studies have shown

Vibrational Modes and Quantum Zero-Point Energy of Hydrogen in ZrH 0.0155 and ZrH 2

March 25, 2020
Author(s)
Timothy R Prisk, Alexander I. Kolesnikov, Garrett E. Granroth, Jun-li Lin, Brent J. Heuser
We report on an inelastic neutron scattering study of the proton dynamics in ZrH 0.0155 and -ZrHd2^. In particular, we present measurements of the incoherent dynamic structure factor, generalized vibrational density of states, and proton momentum

Nd Ordering, Cluster Formation, and the Origin of Negative Magnetization in NdMn 0l8 Fe 0.2 O 3=d

March 1, 2020
Author(s)
D. M. Pajerowski, Jr. C. A. Escanhoela, D. Haskel, Timothy R Prisk, M. D. Frontzek, D. Phelan, Jr. Mihalik, M. Mihalik
The orthorhombic pseudo-perovskite series NdMn 1-xFe xO 3+δ has negative magnetization, i.e. magnetization directed opposite to an applied field under certain conditions, for x = 0.3 and x=0.25. We have investigated the microscopic origin of this

Magnetic Ground State and Magnetic Excitations in Black Dioptase Cu 6 Si 6 O 18

November 1, 2019
Author(s)
A. Podlesnyak, O. Prokhnenko, S. E. Nikitin, A. I. Kolesnikov, M. Matsuda, Sachith E. Dissanayake, Timothy R Prisk, H. Nojiri, I. F. Diaz-Ortega, L. M. Anovitz
The low-temperature magnetic properties and magnetic structure of fully dehydrated black dioptase Cu 6Si 6O 18 have been studied by single-crystal neutron diffraction and magnetization measurements in magnetic fields up to 30 T. The intrachain J c and

Homogeneous Reduced Moment in a Gapful Scalar Chiral Kagome Antiferromagnet

July 12, 2019
Author(s)
A. Scheie, S. Dasgupta, M. Sanders, A. Sakai, Y. Matsumoto, Timothy R Prisk, S. Nakatsuji, R. J. Cava, Collin L. Broholm
We present a quantitative experimental investigation of the scalar chiral magnetic order with in Nd 3Sb 3Mg 2O 14. Static magnetization reveals a net ferromagnetic ground state, and inelastic neutron scattering from the hyperfine coupled nuclear spin

Direct Measurement of Hydrogen Diffusivity and Solubility Limits in Zircaloy 2 (Formula Unit of ZrH 0.0155 ) using Incoherent Quasi-Elastic Neutron Scattering

May 1, 2019
Author(s)
Brent J. Heuser, Timothy R Prisk, Jun-li Lin, Tanya J. Dax, Yongfeng Zhang
The diffusivity of hydrogen is an important property of light water nuclear reactor (LWR) fuel cladding. LWR cladding absorbs hydrogen during normal operation, a contributing factor to embrittlement that decreases the lifetime of the fuel. Mass transport

Inelastic and Deep Inelastic Neutron Spectroscopy of Water Molecules under Ultra-Confinement

July 1, 2018
Author(s)
A. I. Kolesnikov, G. F. Reiter, Timothy R Prisk, M. Krzystyniak, G. Romanelli, D. J. Wesolowski, Lawrence M. Anovitz
Water confined within sub-nanometer channels of silicate minerals presents an extreme case of confinement, where the restricted molecules are situated in channels whose diameter is not much larger than the water molecule itself. Recently, we discovered a

The Momentum Distribution of Liquid 4 He

November 1, 2017
Author(s)
Timothy R Prisk, M. S. Bryan, P. E. Sokol, G. E. Granroth, S. Moroni, M. Boninsegni
We report high-resolution neutron Compton scattering measurements of liquid 4He under saturated vapor pressure. There is excellent agreement between the observed scattering and ab initio predictions of its lineshape. quantum Monte Carlo calculations

Bulklike Excitations in Nanoconfined Liquid Helium

April 20, 2017
Author(s)
M. S. Bryan, Timothy R Prisk, T. E. Sherline, S. O. Diallo, P. E. Sokol
Liquid helium confined in porous media provides a model system for studying the effects of confinement, disorder, and reduced dimensionality upon a strongly interacting Bose fluid. The effects of extreme, nanoscale confinement upon its microscopic

The Momentum Distribution of Liquid 3 He

September 1, 2016
Author(s)
M. S. Bryan, Timothy R Prisk, Richard Azuah, W. G. Stirling, P.E. Sokol
We present high-resolution neutron Compton scattering measurements of liquid 3He below its renormalized Fermi temperature. Theoretical predictions are in excellent agreement with the experimental data when instrumental resolution and final state effects