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Sven Ulrich

Other affiliations: RWTH Aachen University
Bio: Sven Ulrich is an academic researcher from Karlsruhe Institute of Technology. The author has contributed to research in topics: Sputter deposition & Thin film. The author has an hindex of 26, co-authored 124 publications receiving 2191 citations. Previous affiliations of Sven Ulrich include RWTH Aachen University.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a review of the latest developments in hard, wear-resistant thin films based on the multilayer coating concept is presented, covering various phenomena such as the superlattice effect, stabilization of materials in another, foreign structure, and effects related to coherent and epitaxial growth.

260 citations

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TL;DR: A new compact electrically controlled surface plasmon polariton (SPP) absorption modulator operating at communication wavelengths is introduced.
Abstract: An electrically controlled ultra-compact surface plasmon polariton absorption modulator (SPPAM) is proposed. The device can be as small as a few micrometers depending on the required extinction ratio and the acceptable loss. The device allows for operation far beyond 100 Gbit / s, being only limited by RC time constants. The absorption modulator comprises a stack of metal / insulator / metal-oxide / metal layers, which support a strongly confined asymmetric surface plasmon polariton (SPP) in the 1.55 μm telecommunication wavelength window. Absorption modulation is achieved by electrically modulating the free carrier density in the intermediate metal-oxide layer. The concept is supported by proof-of-principle experiments.

250 citations

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TL;DR: The present guidelines for TDM application for neuropsychiatric agents aim to assist clinicians in enhancing safety and efficacy of treatment.
Abstract: Objectives: Therapeutic drug monitoring (TDM) combines the quantification of drug concentrations in blood, pharmacological interpretation and treatment guidance. TDM introduces a precision medicine...

92 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive literature review on hard multilayer coatings, which contain TiN and/or ZrN as a component is given, starting with the first published results in 1987 and ending with the latest articles in 2005, were summarized and critically evaluated in order to serve as a starting point for future research in this area.
Abstract: In the first part of this article, a comprehensive literature review on hard multilayer coatings, which contain TiN and/or ZrN as a component is given. The developments made in this field, starting with the first published results in 1987 and ending with the latest articles in 2005, were summarized and critically evaluated in order to serve as a starting point for future research in this area. In the second part, recent progress in the nanoscale characterization of multilayers and their interfaces by the small-angle cross-section nanoindentation method and atomic force microscopy is demonstrated on TiN∕ZrN multilayers. These nanoscale multilayers were deposited by reactive dc-magnetron sputtering of metallic titanium and zirconium targets in argon/nitrogen plasma onto hard metal and silicon substrates.

87 citations

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TL;DR: In this paper, the influence of the sputtering atmosphere, the substrate temperature and the substrate bias on the composition and on the mechanical and microstructural properties of the thin films was investigated.
Abstract: Thin films of silicon nitride (Si3N4) and silicon carbide (SiC) have been deposited by radio frequency (r.f.) magnetron sputtering of stoichiometric targets in non-reactive argon and in the case of Si3N4 additionally in reactive nitrogen–argon atmospheres. The influence of the sputtering atmosphere, the substrate temperature and the substrate bias on the composition and on the mechanical and microstructural properties of the thin films was investigated. FTIR and Raman spectroscopy was used to identify the chemical bonding configuration and to control the chemical composition. Raman investigation showed a change in the bonding configuration from amorphous silicon carbide to a crystalline structure and the incorporation of nitrogen in silicon nitride thin films with increasing substrate bias.

73 citations


Cited by
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Journal ArticleDOI
10 Mar 1970

8,159 citations

Journal ArticleDOI
TL;DR: This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent conducting oxides, perovskiteOxides, metal nitrides, silicides, germanides, and 2D materials such as graphene.
Abstract: Materials research plays a vital role in transforming breakthrough scientific ideas into next-generation technology. Similar to the way silicon revolutionized the microelectronics industry, the proper materials can greatly impact the field of plasmonics and metamaterials. Currently, research in plasmonics and metamaterials lacks good material building blocks in order to realize useful devices. Such devices suffer from many drawbacks arising from the undesirable properties of their material building blocks, especially metals. There are many materials, other than conventional metallic components such as gold and silver, that exhibit metallic properties and provide advantages in device performance, design flexibility, fabrication, integration, and tunability. This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent conducting oxides, perovskite oxides, metal nitrides, silicides, germanides, and 2D materials such as graphene. This review provides a summary of the recent developments in the search for better plasmonic materials and an outlook of further research directions.

1,836 citations

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TL;DR: This Review discusses model high-entropy alloys with interesting properties, the physical mechanisms responsible for their behaviour and fruitful ways to probe and discover new materials in the vast compositional space that remains to be explored.
Abstract: Alloying has long been used to confer desirable properties to materials. Typically, it involves the addition of relatively small amounts of secondary elements to a primary element. For the past decade and a half, however, a new alloying strategy that involves the combination of multiple principal elements in high concentrations to create new materials called high-entropy alloys has been in vogue. The multi-dimensional compositional space that can be tackled with this approach is practically limitless, and only tiny regions have been investigated so far. Nevertheless, a few high-entropy alloys have already been shown to possess exceptional properties, exceeding those of conventional alloys, and other outstanding high-entropy alloys are likely to be discovered in the future. Here, we review recent progress in understanding the salient features of high-entropy alloys. Model alloys whose behaviour has been carefully investigated are highlighted and their fundamental properties and underlying elementary mechanisms discussed. We also address the vast compositional space that remains to be explored and outline fruitful ways to identify regions within this space where high-entropy alloys with potentially interesting properties may be lurking. High-entropy alloys have greatly expanded the compositional space for alloy design. In this Review, the authors discuss model high-entropy alloys with interesting properties, the physical mechanisms responsible for their behaviour and fruitful ways to probe and discover new materials in the vast compositional space that remains to be explored.

1,798 citations