| AVS 60th International Symposium and Exhibition | |
| Magnetic Interfaces and Nanostructures | Tuesday Sessions |
| Session MI+AS+NS+SP-TuA |
| Session: | Advanced Probes in Magnetic Imaging and Characterization |
| Presenter: | P. Fischer, Lawrence Berkeley National Laboratory |
| Authors: | P. Fischer, Lawrence Berkeley National Laboratory M.-Y. Im, Lawrence Berkeley National Laboratory W. Chao, Lawrence Berkeley National Laboratory E.H. Anderson, Lawrence Berkeley National Laboratory |
| Correspondent: | Click to Email |
Nanomagnetism research focused on a fundamental understanding and controlling spins on a nanoscale. As the next step beyond the nanoscale, mesoscale phenomena have been recognized[1], since those add essential parameters to meet future challenges in terms of speed, size and energy efficiency of spin driven devices. The development and application of multidimensional visualization techniques, such as tomographic magnetic imaging will be crucial to achieve mesoscience goals.
Magnetic soft X-ray microscopy is a unique analytical technique combining X-ray magnetic circular dichroism (X-MCD) as element specific magnetic contrast mechanism with high spatial and temporal resolution [2]. Three-dimensional (3D) soft X-ray tomography using Fresnel zone plate based full field and scanning transmission soft x-ray microscopies have been developed and are routinely used at various synchrotron sources but mostly for biological imaging [3]. However, magnetic X-ray tomography is of large interest to understand e.g. interfaces in magnetic multilayers, the inner structure of magnetic nanocrystals, nanowires or the functionality of artificial 3D magnetic nanostructures.
There are several approaches for 3D X-ray imaging, such as utilizing standing waves in Bragg conditions [3], X-ray imaging in reflection geometry [4], X-ray ptychography [5] or computational reconstruction of projection X-ray images [6]. We have developed and implemented at the full-field soft X-ray microscopy beamline 6.1.2 at the ALS in Berkeley CA a new stage for tomography, which allows recording an angular series (up to 360 deg) of high precision 2D projection images. Applying state-of-the-art reconstruction algorithms it is possible to retrieve the full 3D structure. We will present recent results on prototype systems, such as glass capillaries coated with magnetic films . We will also discuss the complementarity of magnetic X-ray tomography to other 3D imaging approaches such as electron microscopy [7].
This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Dept. of Energy under Contract No. DE-AC02-05-CH11231.
[1] BESAC report: From Quanta to the Continuum: Opportunities for Mesoscale Science (2012), http://science.energy.gov/~/media/bes/pdf/reports/files/OFMS_rpt.pdf
[2] P. Fischer, Materials Science & Engineeering R72 81 (2011)
[3] A.X. Gray, et al. Appl Phys Lett 97, 062503 (2010)
[4] G. Denbeaux, et al. IPAP Conf. Series 7 pp.375-386 (2006)
[5] D.Y. Parkinson et al, J. Struct. Biology 177 259 (2012)
[6] M. Dierolf et al. Nature 467, 436 (2010)
[7] C. Phatak et al, Ultramicroscopy 109 264 (2009)