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Search Publications by: Justin Shaw (Fed)

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Displaying 26 - 50 of 162

Magnetoelasticity of Co 25 Fe 75 thin films

August 20, 2019
Author(s)
Daniel Schwienbacher, Matthias Pernpeintner, Lukas Liensberger, Eric R. Edwards, Hans Nembach, Justin Shaw, Mathias Weiler, Rudolf Gross, Hans Huebl
We investigate the magnetoelastic properties of Co 25Fe 75 and Co 10Fe 90 thin films by measuring the mechanical properties of a doubly clamped string resonator covered with multilayer stacks containing these films. For the magnetostrictive constants, we

Near-Unity Spin Hall Ratio in Ni$_x$Cu$_{1-x}$ Alloys

June 7, 2019
Author(s)
Mark W. Keller, Katy Gerace, Monika Arora, Justin M. Shaw, Thomas J. Silva
We report a large spin Hall effect in the 3$d$ transition metal alloy Ni$_x$Cu$_{1-x}$ for $x \in \{ 0.3,0.75\} $, detected via the ferromagnetic resonance of a permalloy (Py = Ni$_{80}$Fe$_{20}$) film deposited in a bilayer with the alloy. A thickness

Co 25 Fe 75 Thin Films with Ultralow Total Damping

May 13, 2019
Author(s)
Eric R. Edwards, Hans T. Nembach, Justin M. Shaw
We measure the dynamic properties of Co 25Fe 75 thin films grown by dc magnetron sputtering. Using ferromagnetic resonance spectroscopy, we demonstrate an ultralow total damping parameter in the out-of-plane configuration of 0.0013, whereas for the in

Domain-wall motion and interfacial Dzyaloshinskii-Moriya interactions in Pt/Co/Ir(tIr)/Ta multilayers

March 7, 2019
Author(s)
Kowsar Shahbazi, Joo-Von Kim, Hans Nembach, Justin Shaw, Andreas Bischof, Marta Rossell, Vincent Jeudy, Thomas A. Moore, Christopher H. Marrows
The interfacial Dzyaloshinskii-Moriya interaction (DMI) is important for chiral domain walls (DWs) and for stabilizing magnetic skyrmions. We study the effects of introducing increasing thicknesses of Ir, from zero to 2 nm, into a Pt/Co/Ta multilayer

Controlling the polarization and vortex charge of attosecond high-harmonic beams via simultaneous spin-orbit momentum conservation

December 10, 2018
Author(s)
Kevin Dorney, Laura Rego, Nathan J. Brooks, Julio San Roman, Chen-Ting Liao, Jennifer Ellis, Dmitriy Zusin, Christian Gentry, Quynh Nguyen, Justin Shaw, Antonio Picon, Luis Plaja, Henry C. Kapteyn, Margaret M. Murnane, Carlos Hernandez-Garcia
Optical interactions are governed by both spin and angular momentum conservation laws, which serve as a tool for controlling light-matter interactions or elucidating electron dynamics and structure of complex systems. Here, we uncover a form of

Inhomogeneous magnon scattering during ultrafast demagnetization

October 25, 2018
Author(s)
Ronny J. Knut, Erna Delczeg-Czirjak, Somnath Jana, Justin M. Shaw, Hans T. Nembach, Yaroslav Kvashnin, Robert Stefaniuk, Rameez Malik, Patrik Grychtol, Dmitriy Zusin, Christian Gentry, Raghuveer Chimata, Manuel Pereiro, Johan Soderstrom, Emrah Turgut, Martina Ahlberg, Johan Akerman, H C. Kapteyn, Margaret M. Murnane, Dario A. Arena, Olle Eriksson, Olof Karis, Thomas J. Silva
Ni 0.8Fe 0.2 (Py) and Py alloyed with Cu exhibit intriguing ultrafast demagnetization behavior, where the Ni magnetic moment shows a delayed response relative to the Fe, an effect which is strongly enhanced by Cu alloying. We have studied a broad range of

Localization of Fe d-states in Ni-Fe-Cu alloys and implications for ultrafast demagnetization

October 20, 2018
Author(s)
Ronny J. Knut, Erna Delczeg, Justin Shaw, Hans Nembach, Patrik Grychtol, Dmitriy Zusin, Christian Gentry, Emrah Turgut, Henry C. Kapteyn, Margaret M. Murnane, Dario A. Arena, Olle Eriksson, Olof Karis, Thomas J. Silva
Ni 80Fe 20 (Py) and Py-Cu exhibit intriguing ultrafast demagnetization behavior, where the Ni magnetic moment shows a delayed response relative to the Fe [S. Mathias et al., PNAS \bf 109}, 4792 (2012)]. To unravel the mechanism responsible for this

High harmonics with spatially varying ellipticity for spatially-resolved magnetic spectroscopy

April 17, 2018
Author(s)
Daniel D. Hickstein, Jennifer Ellis, Kevin M. Dorney, Nathan J. Brooks, Christian Gentry, Justin M. Shaw, Quynh Nguyen, Christopher A. Mancuso, Henry C. Kapteyn, Margaret M. Murnane, Carlos Hernandez-Garcia
In this work, we present a new method to produce ultrashort pulses of circularly polarized extreme ultraviolet light. We combine two orthogonally-polarized high-harmonic sources to produce a far-field beam with a uniform intensity distribution but with a

Magnetic properties in ultra-thin 3d transition metal alloys II: experimental verification of quantitative theories of damping and spin-

April 7, 2018
Author(s)
Martin A. Schoen, Juriaan Lucassen, Hans T. Nembach, Thomas J. Silva, Bert Koopmans, Christian Back, Justin M. Shaw
A systematic study of the Gilbert damping is performed via ferromagnetic resonance for the disordered crystalline binary 3d transition metal alloys NiCo, NiFe and CoFe over the whole range of alloy compositions. After accounting for the inhomogeneous

Magnetic properties of ultra-thin 3d transition metal alloys I: spin and orbital moments and confirmation of Slater-Pauling theory

April 7, 2018
Author(s)
Martin A. Schoen, Juriaan Lucassen, Hans T. Nembach, Thomas J. Silva, Bert Koopmans, Christian Back, Justin M. Shaw
The structure and static magnetic properties - saturation magnetization, perpendicular anisotropy, Landé g-factor, and orbital magnetization - of thin film 3d transition metal alloys are determined over the full range of alloy compositions, via X-ray

Magnetic damping in sputtered Co2MnGe Heusler compounds with A2, B2 and L21 order: Experiment and Theory

March 19, 2018
Author(s)
Justin M. Shaw, Eric R. Edwards, Martin A. Schoen, Michael L. Schneider, Matthew R. Pufall, Thomas J. Silva, Hans T. Nembach, Erna Delczeg
We show that very low values of the magnetic damping parameter can be achieved in sputter deposited poly-crystalline films of Co2MnGe annealed at relatively low temperatures ranging from 240 oC to 400 oC. Damping values as low as 0.0014 are achieved with