Multi-color magnetic imaging

Nanoscale magnetic domain networks in Co/Pt heterostructure are spatially resolved through coherent imaging with Fourier-transform holography. Irradiating the holographic sample at the same time with two harmonics of the FEL seed, at resonance with O and Pt respectively, two element specific images are retrieved at the same time.

Willems et al., Structural Dynamics, 4, 014301 (2017).

Multi-color resonant holography of Co/Pd domains

The Co/Pd magnetic specimen is covered by a gold holographic mask with 60 - 80 nm reference holes and a 2 μm wide circular sample area. Diffraction patterns are taken on a CCD when the sample is illuminated by FEL pulses with left and right circular polarization. A holographic image of the magnetic domains is retrieved as the Fourier transform of the difference between the two images, to enhance the magnetic contribution. 

A wavelength scan is performed on the same sample to measure the magnetic scattering cross section, across the M-edge resonance of both Co and O. Tuning different sections of the FERMI@Elettra FEL to different harmonics of the same seed pulse, the sample can be simultaneously irradiated with two-color pulses close to both resonances and a double hologram can be retrieved, providing two different elemental sensitive images of the magnetic domains at the same time.

Multi-color, real-space spectroscopy at FEL sources can become a valuable tool to unravel ultrafast interactions within the electronic and spin structure of complex multicomponent and multiphase materials.

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Multi-color imaging of magnetic Co/Pt heterostructures .

Willems F., von Korff Schmising C., Weder D., Günther C. M., Schneider M., Pfau B., Meise S., Guehrs E., Geilhufe J., El Din Merhe A., Jal E., Vodungbo B., Lüning J., Mahieu B., Capotondi F., Pedersoli E., Gauthier D., Manfredda M., Eisebitt S.

Structural Dynamics, 4, 014301 (2017).

DOI: 10.1063/1.4976004

Last Updated on Thursday, 11 May 2017 16:02