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 by: William D. Ratcliff (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 51

reductus: A Stateless Python Data-Reduction Service with a Browser Frontend

October 1, 2018
Author(s)
Brian B. Maranville, William D. Ratcliff, Paul A. Kienzle
The online data reduction service reductus transforms measurements in experimental science from laboratory coordinates into physically meaningful quantities with accurate estimation of uncertainties based on instrumental settings and properties. This

Fe 2 MnGe: A Hexagonal Heusler Analogue

August 20, 2018
Author(s)
S. Keshavarz, N. Naghibolashrafi, Michelle E. Jamer, K. Vinson, D. Mazumdar, Cindi L. Dennis, William D. Ratcliff, Julie Borchers, A. Gupta, P. LeClair
Fe 2MnGe is a potential half-metallic full-Heusler L2 1 ferromagnetic compound with large spin polarization (approximately equal}97%) useful for various spintronic applications according to our first principles calculations using density functional theory

Mechanical Control of Crystal Symmetry and Superconductivity in Weyl Semimetal MoTe 2

July 30, 2018
Author(s)
Colin A Heikes, I Lin NMN Liu, Tristin Metz, Christoper Eckberg, Paul Michael Neves, Yan Wu, Linda NMN Hung, Phil Piccoli, Huibo Cao, Juscelino Leao, Johnpierre Paglione, Taner Yildirim, Nicholas P. Butch, William D. Ratcliff
The concept of topological order applied to condensed matter systems has inspired extensive experimental and theoretical searches for novel types of quantum matter. Topological superconductivity, where a bulk superconducting state and non-trivial topology

Pressure Tuning of Collapse of Helimagnetic Structure in Au 2 Mn

November 27, 2017
Author(s)
I Lin NMN Liu, Maria J. Pascale, Juscelino Leao, Craig Brown, William D. Ratcliff, Qingzhen Huang, Nicholas Butch
We identify the phase boundary between spiral spin and ferromagnetic phases in Au 2Mn at a critical pressure of 16.4 kbar, as determined by neutron diffraction, magnetization and magnetoresistance measurements. The temperature-dependent critical field at a

Structural and Magnetic Phase Transitions in Chromium Nitride Thin Films Grown by RF Nitrogen Plasma Molecular Beam Epitaxy

September 26, 2017
Author(s)
Khan Alam, Steven M.T. Disseler, William D. Ratcliff, Julie Borchers, Rodrigo Ponce-Perez, Gregorio H. Cocoletzi, Noboru Takeuchi, Andrew Foley, Andrea Richard, David C. Ingram, Arthur R. Smith
A magneto-structural phase transition is investigated in single crystal CrN thin films grown by rf plasma molecular beam epitaxy on MgO(001) substrates. While still within the vacuum environment following MBE growth, in-situ variable low-temperature

Successive Field-Induced Transitions in BiFeO 3 Around Room Temperature

July 21, 2017
Author(s)
Shiro Kawachi, Atsushi Miyake, Toshimitsu Ito, Sachith E. Dissanayake, Masaaki Matsuda, William D. Ratcliff, Yang Zhao, Shin Miyahara, Masashi Tokunaga
The Effects of high magnetic fields applied perpendicular to the spontaneous ferroelectric polarization on single crystals of BiFeO 3 were investigated through magnetization, magnetostriction, and neutron diffraction measurements. The magnetostriction

Electric-Field Induced Reversible Switching of the Magnetic Easy Axis in Co/BiFeO 3 on SrTiO 3

April 18, 2017
Author(s)
Tieren Gao, Xiaohang Zhang, William D. Ratcliff, Shingo Maruyama, Makoto Murakami, Anbusathaiah Varatharajan, Zahra Yamani, Peijie Chen, Ke Wang, Huairuo Zhang, Robert D. Shull, Leonid A. Bendersky, John Unguris, R. Ramesh, Ramamoorthy Ramesh, I. Takeuchi
We demonstrate reversible electric-field-induced switching of the magnetic state of the Co layer in Co/BiFeO 3 (BFO) (001) thin film heterostructures fabricated on (001) SrTiO 3 substrates. The angular dependence of the coercivity and the remanent

Tailoring Exchange Couplings in Magnetic Topological Insulator/Antiferromagnet Heterostructures

January 1, 2017
Author(s)
Qing Lin He, Xufeng Kou, Alexander Grutter, Gen Yin, Lei Pan, Xiaoyu Che, Yuxiang Liu, Tianxiao Nie, Bin Zhang, Steven M.T. Disseler, Brian Kirby, William D. Ratcliff, Qiming Shao, Koichi Murata, Xiaodan Zhu, Guoqiang Yu, Yabin Fan, Mohammad Montazeri, Xiaodong Han, Julie Borchers, Kang L. Wang
Magnetic topological insulators such as Cr-doped (Bi,Sb) 2Te 3 provide a platform for the realization of versatile time-reversal symmetry-breaking physics. By constructing heterostructures with the unique Neel order in an antiferromagnetic CrSb and the

Bayesian Method for the Analysis of Diffraction Patterns using BLAND

December 1, 2016
Author(s)
Joseph E. Lesniewski, Steven M.T. Disseler, Dylan J. Quintanta, Paul A. Kienzle, William D. Ratcliff
Rietveld refinement of x-ray and neutron diffraction patterns is routinely used to solve crystal and magnetic structures of organic and inorganic materials over many length scales. Despite its success over the last several decades, conventional Rietveld

Atomically Engineered Ferroic Layers Yield a Room-Temperature Magnetoelectric Multiferroic

September 21, 2016
Author(s)
Julia A. Mundy, Charles M. Brooks, Megan E. Holtz, Jarrett A. Moyer, Hena Das, Alejandro F. Rebola, John T. Heron, James D. Clarkson, Steven M.T. Disseler, Zhiqi Liu, Alan Farhan, Rainer Held, Robert Hovden, Elliot Padgett, Qingyun Mao, Hanjong Paik, Rajiv Misra, Lena F. Kourkoutis, Elke Arenholz, Andreas Scholl, Julie Borchers, William D. Ratcliff, Ramamoorthy Ramesh, Craig J. Fennie, Peter Schiffer, David A. Muller, Darrell G. Schlom
The defining feature of ferroics is the ability of an external stimulus - electric field, magnetic field, or stress-to move domain walls. These topological defects and their motion enables many useful attributes, e.g., memories that can be reversibly

Chapter 5: Multiferroics

December 24, 2015
Author(s)
William D. Ratcliff, Jeffrey W. Lynn
Multiferroics are insulating materials that are simultaneously magnetically ordered and ferroelectric. From a fundamental standpoint it is interesting to understand the properties and coupling of these two disparate types of order. These materials could

One Dimensional(1D)-to-2D Crossover of Spin Correlations in the 3D Magnet ZnMn 2 O 4

December 8, 2015
Author(s)
Steven M.T. Disseler, Ying Chen, S. Yeo, G. Gasparovic, P.M.B. Piccoli, A. J. Schultz, Yiming Qiu, Qingzhen Huang, S.-W. Cheong, William D. Ratcliff
We report on the intriguing evolution of the dynamical spin correlations of the frustrated spinel ZnMn 2O 4. Inelastic neutron scattering and magnetization studies reveal that the dynamical correlations at high temperatures are 1D. At lower temperature

Multiferroicity in Doped Hexagonal LuFeO 3

August 27, 2015
Author(s)
Steven M. Disseler, Xuan Luo, Bin Gao, Yoon Seok Oh, Rongwei Hu, Yazhong Wang, Dylan Quintana, Alexander Zhang, Qingzhen Huang, June W. Lau, Rick L. Paul, Jeffrey W. Lynn, Sang-Wook Cheong, William D. Ratcliff
The hexagonal phase of LuFeO 3 is a rare example of a multiferroic material possessing a weak ferromagnetic moment, which is predicted to be switchable by an electric field. We stabilize this structure in bulk form through Mn and Sc doping, and determine

Magnetic Structure and Ordering of Multiferroic Hexagonal LuFeO 3

May 29, 2015
Author(s)
Steven M. Disseler, Julie A. Borchers, Charles M. Brooks, Julia A. Mundy, Jarrett A. Moyer, Daniel A. Hillsberry, Eric L. Thies, Dmitri A. Tenne, John Heron, Megan Holtz, James D. Clarkson, Gregory M. Stiehl, Peter Schiffer, David A. Muller, Darrell G. Schlom, William D. Ratcliff
We report on the magnetic structure and ordering of hexagonal LuFeO 3 films of variable thickness grown by molecular-beam epitaxy (MBE) on YSZ (111) and Al 2O 3 (0001) substrates. These crystalline films exhibit long-range structural uniformity dominated

Change in the Magnetic Structure of (Bi,Sm)FeO 3 Thin Films at the Morphotropic Phase Boundary Probed by Neutron Diffraction

November 1, 2014
Author(s)
Shingo Maruyama, Varatharajan Anbusathaiah, Amy Fennell, Mechthild Enderle, Ichiro Takeuchi, William D. Ratcliff
We report on the evolution of the magnetic structure of BiFeO 3 thin films grown on SrTiO 3 substrates as a function of Sm doping. We determined the magnetic structure using neutron diffration. We found that as Sm increases, the magnetic structure evolves

Complex Structures of Different CaFe 2 As 2 Samples

February 18, 2014
Author(s)
Bayrammurad Saparov, Claudia Cantoni, Minghu Pan, Thomas C. Hogan, William D. Ratcliff, Stephen D. Wilson, Katharina Fritsch, Bruce D. Gaulin, Athena S. Sefat
We use temperature-dependent X-ray and neutron diffraction, low-temperature scanning tunneling microscopy, and room-temperature scanning-transmission electron-microscopy, to investigate the interplay between magnetism and crystal structures in three CaFe

Double-Focusing Thermal Triple-Axis Spectrometer at the NCNR

February 2, 2012
Author(s)
Y. Chen, Sung Chang, Yang Zhao, Songxue Chi, William D. Ratcliff, B. G. Ueland, Ross Erwin
The new thermal triple-axis spectrometer at the NIST Center for Neutron Research (NCNR) is located at the BT-7 beam port. The 165 mm diameter reactor beam is equipped with a selection of Söller collimators, beam-limiters, and pyrolytic graphite (PG) filter

Local Weak Ferromagnetism in Single-Crystalline Ferroelectric BiFeO 3

November 1, 2011
Author(s)
M. Ramazanoglu, M. Laver, William D. Ratcliff, Shannon M. Watson, Wangchun Chen, Andrew Jackson, Karunakar NMN Kothapalli, Seongsu Lee, S.- W. Cheong, V. Kiryukhin
Polarized small-angle neutron scattering studies of single-crystalline multiferroic BefeO 3 reveal a long-wavelength spin density wave generated by 1° spin canting of the spins out of the rotation plane of the antiferromagnetic cycloidal order. This

Nitrogen Contamination in Elastic Neutron Scattering

February 23, 2011
Author(s)
Song Xue Chi, Jeffrey W. Lynn, Ying Chen, William D. Ratcliff, Benjamin Ueland, Nicholas P. Butch, Shanta R. Saha, Kevin Kirshenbaum, Johnpierre Paglione
Nitrogen gas accidentally sealed in a sample container produces various spurious effects in elastic neutron scattering measurements. These effects are systematically investigated and the details of the spurious scattering are presented.

3:1 Magnetization Plateau and Suppression of Ferroelectric Polarization in an Ising Chain Multiferroic

January 26, 2009
Author(s)
Y.-J. Jo, Seoungsu Lee, E. Choi, H. Yi, William D. Ratcliff, Y. Choi, V. Kiryukhin, S.-W. Cheong, L. Balicas
Ferroelectric Ising chain magnet Ca3Co2−xMnxO6 (x≃0.96) was studied in magnetic fields of up to 33 T. Magnetization and neutron-scattering measurements reveal successive metamagnetic transitions from the zero-field ↑↑↓↓ spin configuration to the ↑↑↑↓ state