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:

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 240

Realization of Ground-State Artificial Skyrmion Lattices at Room Temperature

October 8, 2015
Author(s)
Dustin A. Gilbert, Brian B. Maranville, Andy L. Balk, Brian J. Kirby, Peter Fischer, Daniel T. Pierce, John Unguris, Julie A. Borchers, Kai Liu
The topological nature of magnetic skyrmions deriving from broken symmetries leads to extraordinary static and dynamic properties that provide new insight in fundamental problems of magnetism and exciting potentials for exploitation in novel magnetic

Quantitative magnetometry of ferromagnetic nanorods by microfluidic analytical magnetophoresis

September 3, 2015
Author(s)
Andrew L. Balk, Lamar O. Mair, Feng Guo, Carlos M. Hangarter, Pramod Mathai, Robert D. McMichael, Samuel M. Stavis, John Unguris
We introduce an implementation of magnetophoresis to measure the absolute magnetization of ferromagnetic nanorods dispersed in fluids, by analyzing the velocity of single nanorods under an applied magnetic field gradient. A microfluidic guideway prevents

Probing electric field control of magnetism using ferromagnetic resonance

January 29, 2015
Author(s)
Ziyao Zhou, Morgan Trassin, Ya Gao, Yuan Gao, Diana Qiu, Khalid Ashraf, Tianxiang Nan, Xi Yang, Samuel R. Bowden, Daniel T. Pierce, Mark D. Stiles, John Unguris, Ming Liu, Brandon Howe, Gail Brown, Sayeef Salahuddin, Ramamoorthy Ramesh, Nian Sun
A question of fundamental importance in multiferroic materials, such as BiFeO3, is whether the canted moment arising from the Dzyalozhinski-Moriya coupling is switchable with the application of an electric field. Since this canted moment is weak, directly

Interfacial Coupling in Multiferroic/Ferromagnet Heterostructures

April 30, 2013
Author(s)
M. Trassin, J. D. Clarkson, Samuel R. Bowden, j. Liu, J. T. Heron, R. J. Paull, Elke Arenholz, Daniel T. Pierce, John Unguris
We report local probe investigations of the magnetic interaction between BiFeO3 films and a ferromagnetic Co0.9Fe0.1 layer. Within the constraints of intralayer exchange coupling in the Co0.9Fe0.1, the multiferroic imprint in the ferromagnet results in a

Optimization of Spin-triplet Supercurrent in Ferromagnetic Josephson Junctions

March 20, 2012
Author(s)
Benjamin James McMorran, Theresa Ginley, Julie Borchers, Brian Kirby, Brian B. Maranville, John Unguris
In the past year, several groups have observed evidence for long-range spin-triplet, supercurrent in Josephson junctions containing ferromagnetic (F) materials. In our work, the spin-triplet pair correlations are created by non-collinear magnetizations

Formation and structure of 360 and 540 degree domain walls in thin magnetic stripes

February 10, 2012
Author(s)
Youngman Jang, Samuel R. Bowden, Mark Mascaro, John Unguris, Caroline Ross
360˚, 540˚ and other complex transverse domain walls have been created in narrow Co wires connected to injection pads by cycling a magnetic field perpendicular to the wire length. The composite walls, formed by impingement of 180˚ transverse walls of

Magnetization textures in NiPd nanostructures

September 15, 2011
Author(s)
Jean-Yves Chauleau, Benjamin James McMorran, R. Belkhou, Nicolas Bergeard, Tevfik Mente?, Miguel Angel Nino, Andrea Locatelli, John Unguris, Stanislas Rohart, Jacques Miltat, Andre Thiaville
We have observed peculiar magnetization textures in Ni80Pd20 nanostructures, by three different imaging techniques (MFM, XMCD-PEEM and SEMPA). The appearance of diamond-like domains with strong lateral charges, and of weak stripes structures brings into

Electron Vortex Beams with High Quanta of Orbital Angular Momentum

January 14, 2011
Author(s)
Benjamin James McMorran, Amit K. Agrawal, Ian M. Anderson, Andrew A. Herzing, Henri J. Lezec, Jabez J. McClelland, John Unguris
Analogous to vortices in light optical beams, electron optical beams with helical wavefronts carry orbital angular momentum and promise new capabilities for electron microscopy and other applications. We use nanofabricated diffraction holograms in an

Measuring the effects of low energy ion milling on the magnetization of Co/Pd multilayers using scanning electron microscopy with polarization analysis

April 30, 2010
Author(s)
Benjamin James McMorran, Aaron C. Cochran, Randy K. Dumas, Kai Liu, Paul Morrow, Daniel T. Pierce, John Unguris
The dependence of the magnetic properties of Co/Pd multilayer films with very thin individual layers, Co(0.4nm)/Pd(0.6nm), on the energy of ion milling is investigated using scanning electron microscopy with polarization analysis (SEMPA). The effect of Ar