| 1. |
- Bexell, Ulf, et al.
(författare)
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ToF-SIMS depth profiling of (Ga,Mn)As capped with amorphous arsenic : effects of annealing time
- 2006
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 252:19, s. 7252-7254
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Tidskriftsartikel (refereegranskat)abstract
- The influence of annealing time on an amorphous As cap layer and the depth distribution of Mn atoms have been investigated. The results show that a 1600 Å thick As cap layer is completely desorbed after 3 h of annealing time. The depth distributions of Mn indicate that interstitial Mn atoms have diffused to the outer surface and being passivated. The thickness of the Mn passivation layer was around 90 Å.
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| 2. |
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| 3. |
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| 4. |
- Stanciu, V., et al.
(författare)
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Influence of annealing parameters on the ferromagnetic properties of optimally passivated (Ga,Mn)As epilayers
- 2005
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 72:12
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Tidskriftsartikel (refereegranskat)abstract
- The influence of annealing parameters—temperature (Ta) and time (ta)—on the magnetic properties of As-capped (Ga,Mn)As epitaxial thin films has been investigated. The dependence of the transition temperature (TC) on ta marks out two regions. The TC peak behavior, characteristic of the first region, is more pronounced for thick samples, while for the second ("saturated") region the effect of ta is more pronounced for thin samples. A right choice of the passivation medium, growth conditions along with optimal annealing parameters routinely yield TC-values of ~150 K and above, regardless of the thickness of the epilayers
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| 5. |
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| 6. |
- Bailey, W. E., et al.
(författare)
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Detection of microwave phase variation in nanometre-scale magnetic heterostructures
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2025-
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Tidskriftsartikel (refereegranskat)abstract
- The internal phase profile of electromagnetic radiation determines many functional properties of metal, oxide or semiconductor heterostructures. In magnetic heterostructures, emerging spin electronic phenomena depend strongly upon the phase profile of the magnetic field (H) over tilde at gigahertz frequencies. Here we demonstrate nanometre-scale, layer-resolved detection of electromagnetic phase through the radio frequency magnetic field (H) over tilde (rf) in magnetic heterostructures. Time-resolved X-ray magnetic circular dichroism reveals the local phase of the radio frequency magnetic field acting on individual magnetizations (M) over tilde (i) through the susceptibility as (M) over tilde = (chi) over tilde(H) over tilde (rf). An unexpectedly large phase variation, similar to 40 degrees, is detected across spin-valve trilayers driven at 3 GHz. The results have implications for the identification of novel effects in spintronics and suggest general possibilities for electromagnetic-phase profile measurement in heterostructures.
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| 7. |
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| 8. |
- Pilet, N., et al.
(författare)
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Piezoelectricity enhancement of P(VDF/TrFE) by X-ray irradiation
- 2016
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Ingår i: Organic electronics. - : ELSEVIER SCIENCE BV. - 1566-1199 .- 1878-5530. ; 37, s. 257-262
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Tidskriftsartikel (refereegranskat)abstract
- Organic electronics is becoming more and more important because the low level of fabrication and deposition complexity even at large scale makes it a good candidate for future low cost technological product development. P(VDF-TrFE) is a co-polymer of special interest due its ferroelectric property enabling usage in re-programmable non-volatile organic memory and magnetoelectric sensors. Piezo force microscopy (PFM) provides access to the technologically relevant ferroelectric polarisability and its remanent polarization via imaging of the piezoelectric property. Here we use PFM to show that piezoelectric response of a P(VDF-TrFE) film can be enhanced by up to 260 % after soft X-ray irradiation. This enhancement correlates with morphological change of part of the film, from amorphous to crystalline. An optimal irradiation dose is found above which the film gets eroded and the piezoelectric response gets lowered. (C) 2016 Elsevier B.V. All rights reserved.
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| 9. |
- Warnicke, P., et al.
(författare)
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Exploring the accessible frequency range of phase-resolved ferromagnetic resonance detected with x-rays
- 2013
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 113:3, s. 033904-
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Tidskriftsartikel (refereegranskat)abstract
- We present time-and element-resolved measurements of the magnetization dynamics in a ferromagnetic trilayer structure. A pump-probe scheme was utilized with a microwave magnetic excitation field phase-locked to the photon bunches and x-ray magnetic circular dichroism in transmission geometry. Using a relatively large photon bunch length with a full width at half maximum of 650 ps, the precessional motion of the magnetization was resolved up to frequencies of 2.5 GHz, thereby enabling sampling at frequencies significantly above the inverse bunch length. By simulating the experimental data with a numerical model based on a forced harmonic oscillator, we obtain good correlation between the two. The model, which includes timing jitter analysis, is used to predict the accessible frequency range of x-ray detected ferromagnetic resonance.
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| 10. |
- Wei, Yajun, et al.
(författare)
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Magnetic coupling in asymmetric FeCoV/Ru/FeNi trilayers
- 2014
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550.
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Konferensbidrag (refereegranskat)abstract
- We have investigated the magnetic anisotropy and interlayer coupling in trilayer films of permendur(100 angstrom)/Ru/permalloy(100 angstrom), with the thickness of the Ru spacer varying from 0 to 200 angstrom. While the permendur/permalloy sample exhibits a small in-plane uniaxial magnetic anisotropy with H-u = 27 Oe, all trilayers are magnetically isotropic in-plane. Results from hysteresis loop and ferromagnetic resonance measurements were fitted to a micromagnetic model, with the results indicating that all the films are ferromagnetically coupled except the one with 10 angstrom Ru spacer, which shows antiferromagnetic coupling. The trilayers with Ru spacer layer thickness larger than 20 angstrom exhibit only very weak ferromagnetic coupling. (C) 2014 AIP Publishing LLC.
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