| 1. |
- Baraldi, Alessandro, et al.
(författare)
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The (1x1)-> hexagonal structural transition on Pt(100) studied by high-energy resolution core level photoemission
- 2007
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 127:16
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Tidskriftsartikel (refereegranskat)abstract
- The (1 x 1)-> quasihexagonal (HEX) phase transition on a clean Pt(100) surface was investigated by monitoring the time evolution of the Pt4f(7/2) core level photoemission spectra. The spectral component originating from the atoms forming the (1 x .1) metastable unreconstructed surface was found at -570 +/- 20 meV with respect to the bulk peak. Ab initio calculations based on density functional theory confirmed the experimental assignment. At temperatures above 370 K, the (1 x 1) phase irreversibly reverts to the more stable HEX phase, characterized by a surface core level shifted component at -185 +/- 40 meV. By analyzing the intensity evolution of the core level components, measured at different temperatures in the range of 393-475 K, we determined the activation energy of the phase transformation, E=0.76 +/- 0.04 eV. This value is considerably lower than the one previously determined by means of low energy electron diffraction. Possible reasons for this discrepancy are discussed.
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| 2. |
- Casals, Blai, et al.
(författare)
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Generation and Imaging of Magnetoacoustic Waves over Millimeter Distances
- 2020
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Ingår i: PHYSICAL REVIEW LETTERS. - 0031-9007 .- 1079-7114. ; 124:13
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Tidskriftsartikel (refereegranskat)abstract
- Using hybrid piezoelectric-magnetic systems we have generated large amplitude magnetization waves mediated by magnetoelasticity with up to 25 degrees variation in the magnetization orientation. We present direct imaging and quantification of both standing and propagating acoustomagnetic waves with different wavelengths, over large distances up to several millimeters in a nickel thin film.
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| 3. |
- Khaliq, Muhammad Waqas, et al.
(författare)
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GHz sample excitation at the ALBA-PEEM
- 2023
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Ingår i: Ultramicroscopy. - 0304-3991. ; 250
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Tidskriftsartikel (refereegranskat)abstract
- We describe a setup that is used for high-frequency electrical sample excitation in a cathode lens electron microscope with the sample stage at high voltage as used in many synchrotron light sources. Electrical signals are transmitted by dedicated high-frequency components to the printed circuit board supporting the sample. Sub-miniature push-on connectors (SMP) are used to realize the connection in the ultra-high vacuum chamber, bypassing the standard feedthrough. A bandwidth up to 4 GHz with -6 dB attenuation was measured at the sample position, which allows to apply sub-nanosecond pulses. We describe different electronic sample excitation schemes and demonstrate a spatial resolution of 56 nm employing the new setup.
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