Soft x-ray studies of nanomagnetic and spintronic materials at Brookhaven National Laboratory
Lead Research Organisation:
University of Leeds
Department Name: Physics and Astronomy
Abstract
The Leeds Condensed Matter Physics Group have been regular users of synchrotron radiation at the NSLS now for over six years, where the unique element-specific sensitivity to magnetism of polarized soft x-rays has made great contributions to our research in studying disorder, anisotropy and hysteresis in a variety of nanomagnetic systems. Here we request travel funding to allow us to pursue here two main avenues of research in our new two year user programme at that facility. The first is soft x-ray magnetic scattering from arrays of nanomagnets, fabricated at the Brookhaven Center for Functional Nanomaterials, which exhibit frustrated geometries: whilst the underlying physical structure is periodic, the magnetic structure will display only short range order due to the frustration. Off-specular magnetic scattering will allow us to characterize this disorder as a function of sample array geometry, magnetic field, and temperature, yielding complementary information to real space imaging techniques. The second area is in the study of magnetic nanoclusters, formed by gas-phase aggregation and deposited as part of a magnetic multilayer stack such as a tunnel junction. We have the capability to produce very narrow and well-controlled size distributions, so size dependences. Here we will study spin-orbit moment ratios and chemical composition, such as oxidation from surrounding tunnel barrier material, using XMCD spectroscopy. Unlike similar european facilities, synchrotron beamtime at the NSLS does not come with money to support travel to the facility. The experiments form part of our ongoing and highly successful joint programme on magnetic scattering between Leeds and ISIS. The grant request is for travel and subsistence funds only to allow a team of three people to travel to Brookhaven for five weeklong periods in order to operate the experiment 24 hours a day, as well as carry out sample fabrication at the CFN and present our results at conferences.
People |
ORCID iD |
Christopher Marrows (Principal Investigator) |
Publications
Budrikis Z
(2012)
Domain dynamics and fluctuations in artificial square ice at finite temperatures
in New Journal of Physics
Budrikis Z
(2012)
Disorder strength and field-driven ground state domain formation in artificial spin ice: experiment, simulation, and theory.
in Physical review letters
Ciudad D
(2012)
Competition between cotunneling, Kondo effect, and direct tunneling in discontinuous high-anisotropy magnetic tunnel junctions
in Physical Review B
Creeth G
(2011)
Surface morphology and transport studies of epitaxial graphene on SiC( 000 1 _ )
in Physical Review B
Dempsey K
(2010)
Cotunneling enhancement of magnetoresistance in double magnetic tunnel junctions with embedded superparamagnetic NiFe nanoparticles
in Physical Review B
Dempsey K
(2010)
Tuning the coercive field of Ni and CuNi thin films with the embedding of Co nanoparticles: An element-specific study
in Journal of Magnetism and Magnetic Materials
Hindmarch A
(2010)
Magnetostructural influences of thin Mg insert layers in crystalline CoFe(B)/MgO/CoFe(B) magnetic tunnel junctions
in Applied Physics Letters
Hindmarch A
(2010)
Influence of deposition field on the magnetic anisotropy in epitaxial Co 70 Fe 30 films on GaAs(001)
in Physical Review B
Hindmarch A
(2010)
Fe diffusion, oxidation, and reduction at the CoFeB/MgO interface studied by soft x-ray absorption spectroscopy and magnetic circular dichroism
in Applied Physics Letters
Morgan J
(2010)
Thermal ground-state ordering and elementary excitations in artificial magnetic square ice
in Nature Physics
Description | Our findings in this project fall into two categories. First we have used soft x-rays to study spintronic materials such as magntic tunnel junctions and parts thereof, giving insights into the oxidation state and magnetic properties of electrode layers and nanoparticles buried within barriers. Second we have prepared and studied artificial spin ice samples using BNL facilities that have given us new insights into frustration and thermal/athermal properties of artificial statistical mechanical systems. |
Exploitation Route | Spintronics/nanomagnetism based industries such as ICT hardware Networks of industrial contacts |
Sectors | Digital/Communication/Information Technologies (including Software) Electronics |
Description | To develop understanding of the annealling processes in magnetic tunnel junctions |
First Year Of Impact | 2011 |
Sector | Digital/Communication/Information Technologies (including Software),Electronics |
Impact Types | Economic |