| 11. |
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| 12. |
- Fu, Yu, et al.
(författare)
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Mechanism of tailored magnetic anisotropy in amorphous Co68Fe24Zr8 thin films
- 2014
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 104:7, s. 072409-
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Tidskriftsartikel (refereegranskat)abstract
- The mechanism of tailored magnetic anisotropy in amorphous Co68Fe24Zr8 thin films was investigated by ferromagnetic resonance (FMR) on samples deposited without an applied magnetic field, with an out-of-plane field and an in-plane field. Analysis of FMR spectra profiles, high frequency susceptibility calculations, and statistical simulations using a distribution of local uniaxial magnetic anisotropy reveal the presence of atomic configurations with local uniaxial anisotropy, of which the direction can be tailored while the magnitude remains at an intrinsically constant value of 3.0(2) kJ/m(3). The in-plane growth field remarkably sharpens the anisotropy distribution and increases the sample homogeneity. The results benefit designing multilayer spintronic devices based on highly homogeneous amorphous layers with tailored magnetic anisotropy.
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| 13. |
- Fu, Yu, et al.
(författare)
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Tailored magnetic anisotropy in an amorphous trilayer
- 2011
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 109:11, s. 113908-
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Tidskriftsartikel (refereegranskat)abstract
- An amorphous Co68Fe24Zr8(3 nm)/Al70Zr30(3 nm)/Co68Fe24Zr8(3 nm) trilayer system has been investigated using in-plane and out-of-plane angular dependent ferromagnetic resonance at different frequencies. The in-plane magnetic anisotropy is uniaxial, retaining its value of (2.9 +/- 0.1) x 10(3) J/m(3) for each magnetic layer, whereas its direction was tailored independently in an arbitrary manner by applying an external magnetic field during the film deposition. The perpendicular anisotropy constant, supposed to reflect the interface quality, is nearly identical for both layers. Furthermore, the magnetic layers act independently upon each other due to the absence of interlayer coupling.
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| 14. |
- Fu, Yu, et al.
(författare)
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Uniaxial anisotropy and its manipulation in amorphous Co68Fe24Zr8 thin films (invited)
- 2014
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 115:17, s. 172605-
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Tidskriftsartikel (refereegranskat)abstract
- We have proven that the growth of Co68Fe24Zr8 layers under external field yields a uniaxial anisotropy, defined by the direction of the field. No magnetic coupling is present between Co68Fe24Zr8 layers when separated by a 3 nm of Al70Zr30. The anisotropy axis can therefore be manipulated at will and the direction can be tailored, layer by layer in multilayers, by the choice of the direction of the applied field during growth. The g-factor (2.13) and the anisotropy constant, obtained from ferromagnetic resonance, support the existence of short-range order. The relation between the temperature dependences of magnetic anisotropy and magnetization are partially captured by Callen-Callen power law. (C) 2014 AIP Publishing LLC.
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| 15. |
- Lindgren, Per, et al.
(författare)
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RTFM-core : Language and Implementation
- 2014
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Konferensbidrag (refereegranskat)abstract
- Robustness, real-time properties and resource eciency arekey properties to embedded devices of the CPS/IoT era. Inthis paper we propose a language approach RTFM-core,and show its potential to facilitate the development processand provide highly ecient implementations amendablefor static verication. Our programming model is reactive,based on the familiar notions of concurrent tasksand (single-unit) resources. The language is kept minimalistic,capturing the static task, communication and resourcestructure of the system. Whereas C-source can be arbitrarilyembedded in the model, and/or externally referenced,the instep to mainstream development is minimal, and asmooth transition of legacy code is possible. A prototypecompiler implementation for RTFM-core is presented. Thecompiler generates C-code output that compiled togetherwith the RTFM-kernel primitives runs on bare metal. TheRTFM-kernel guarantees deadlock-lock free execution andeciently exploits the underlying interrupt hardware forstatic priority scheduling and resource management underthe Stack Resource Policy. This allows a plethora of wellknownmethods to static verication (response time analysis,stack memory analysis, etc.) to be readily applied. The proposedlanguage and supporting tool-chain is demonstratedby showing the complete process from RTFM-core sourcecode into bare metal executables for a light-weight ARMCortexM3 target.
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| 16. |
- Lindgren, Per, et al.
(författare)
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RTFM-lang static semantics for systems with mixed criticality
- 2014
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Ingår i: Ada User Journal. - 1381-6551. ; 35:2, s. 128-132
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Tidskriftsartikel (refereegranskat)abstract
- In an embedded system, functions often operate under different requirements. In the extreme, a failing safety critical function may cause collateral damage (and hence consider to be a system failure) while non critical functions affect only the quality of service. Approaches by partitioning the system's functions into sandboxes require virtualization mechanisms by the underlying platform and thus prohibit deployment to the bulk of microcontroller based systems. In this paper we discuss an alternative approach based on static semantic analysis performed directly on the system specification expressed in the form of an object oriented (00) model in the experimental language RTFM-lang. This would allow to (at compile time) to discriminate in between critical and non-critical functions, and assign these (by means of statically checkable typing rules) appropriate access rights. In particular, one can imagine dynamic memory allocations to be allowed only in non-critical functions, while on the other hand, direct interaction with the environment may be restricted to the critical parts. With respect to scheduling, a static task and resource configuration allows e.g. Stack Resource Policy (SRP) based approaches to be deployed. In this paper we discuss how this can be achieved in a mixed critical setting.
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