| 1. |
- Etz, Corina, et al.
(författare)
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Ab initio magneto-optical properties of bcc Ni/Ni(100)
- 2008
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 77:6
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Tidskriftsartikel (refereegranskat)abstract
- The inter- and intralayer contributions to the layer-resolved complex optical conductivity tensor for semi-infinite layered systems are calculated in terms of the Luttinger formula within the spin-polarized relativistic screened Korringa-Kohn-Rostoker method. Ab initio Kerr angles are then obtained for arbitrary geometry and incidence via a 2x2 matrix technique including all multiple reflections and all optical interferences. Applied to in-plane single-domain magnetized bcc Ni/Ni(100), it is proven that the assumed appropriate formula of Kerr angles widely used to explain magneto-optical Kerr effect with rotating magnetic field measurements fully agrees with our ab initio Kerr data. From the experimental Kerr data of Tian [Phys. Rev. Lett. 94, 137210 (2005)], however, it cannot be concluded that the deduced magnetic properties apply for bulk Ni, since about 75% of the contributions to the Kerr rotation angle arise from the surface.
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| 2. |
- Etz, Corina, et al.
(författare)
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Magneto-optical properties of Co/Ir superstructures on Ir(111)
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 84:1
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Tidskriftsartikel (refereegranskat)abstract
- The fully relativistic spin-polarized screened Korringa-Kohn-Rostoker method is used to evaluate the electronic and magnetic structure as well as the optical conductivity of (ComIrm)n superstructures on Ir(111). By mapping the microscopic optical conductivity tensor onto the macroscopic permittivity tensor and by using the so-called 2×2 matrix technique the surface reflectivity matrices for these systems are then calculated, from which in turn the Kerr rotation and ellipticity angles can be determined. It is found (i) that when varying at a given value of m the number of repetitions n, these angles are linearly proportional to the total magnetic moment, and (ii) that at a frequency of about 3.8 eV the Kerr rotation angles have the largest value, the corresponding maximum being mainly caused by the Ir spacer layers. The optical properties of the free surface of Ir(111), which is considered to check the applied theoretical schemes, turn out to be in good agreement with existing experimental data.
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| 3. |
- Etz, Corina, et al.
(författare)
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ROTMOKE : An assessment of macroscopic models for bcc Ni/Ni(100)
- 2008
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 88:18-20, s. 2765-2775
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Tidskriftsartikel (refereegranskat)abstract
- Ab-initio Kerr angles for a multilayer system were calculated by means of Luttinger's formalism within the spin-polarized relativistic screened Korringa-Kohn-Rostoker method by including all multiple reflections and optical interferences via the 2 2 matrix technique. Two further macroscopic models are suggested for a multilayer system; i.e., the two-media approach and the three-media approach. The Kerr angles obtained using the two-media approach show that 75 % of the Kerr rotation angles arise from surface contributions when compared to the 2 2 matrix approach. Furthermore, by comparing the three-media approach to the 2 2 matrix technique it is found that almost 25 % of the Kerr rotation angles are due to interfaces between the atomic layers
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| 4. |
- Pirker, Franz, et al.
(författare)
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Tribological Characterisation Services for Materials – i-TRIBOMAT
- 2020
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Ingår i: Tribologie und Schmierungstechnik. - : Expert Verlag. - 0724-3472. ; 67:5-6, s. 35-50
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Tidskriftsartikel (refereegranskat)abstract
- Um den Entwicklungsprozess von neuen Komponenten zu beschleunigen, ist die Vorrausage der Eigenschaften der eingesetzten Werkstoffe im Betrieb der Komponenten von enormer Bedeutung. Um neue Werkstoffe hinsichtlich Ihrer Performance (in einer Komponente) bewerten zu können, ist deshalb die Entwicklung neuer innovativer Methoden notwendig. Diese Methoden können auch unter dem Begriff „lab-to-field“ oder „materials“ – up-scaling zusammengefasst werden. D. h. Werkstoffe werden im Labor charakterisiert, und deren Eigenschaften mittels z.B. Simulation auf die Komponentenperformance hochskaliert (upscaling). i-TRIBOMAT ist ein EU gefördertes Projekt (H2020, GA Nr. 814494) mit dem Ziel ein Open Innovation Test Bed für tribologische Werkstoffcharakterisierung aufzubauen und ent-sprechende Services von der tribologischen Charakterisierung neuer Werkstoffe bis hin zu Simulationsmodellen zur Vorrausage der Perfomance von Komponenten der Industrie anzubieten. Durch die Bündelung von Knowhow und Infrastruktur zu Charakterisierung sowie den Aufbau einer digitalen Plattform, wird i-TRIBOMAT das weltgrößte Open Innovation Test Bed für tribologische Werkstoffcharakterisierung.
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