| 1. |
- Facio, Jorge, et al.
(author)
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Engineering a pure Dirac regime in ZrTe5
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In: SciPost Physics. - 2542-4653.
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Journal article (other academic/artistic)abstract
- Real-world topological semimetals typically exhibit Dirac and Weyl nodes that coexist with trivial Fermi pockets. This tends to mask the physics of the relativistic quasiparticles. Using the example of ZrTe5, we show that strain provides a powerful tool for in-situ tuning of the band structure such that all trivial pockets are pushed far away from the Fermi energy, but only for a certain range of Van der Waals gaps. Our results naturally reconcile contradicting reports on the presence or absence of additional pockets in ZrTe5, and provide a clear map of where to find a pure three-dimensional Dirac semimetallic phase in the structural parameter space of the material.
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| 2. |
- Facio, Jorge I., et al.
(author)
-
Engineering a pure Dirac regime in ZrTe5
- 2023
-
In: SciPost Physics. - : Stichting SciPost. - 2542-4653. ; 14:4
-
Journal article (peer-reviewed)abstract
- Real-world topological semimetals typically exhibit Dirac and Weyl nodes that coexist with trivial Fermi pockets. This tends to mask the physics of the relativistic quasiparti-cles. Using the example of ZrTe5, we show that strain provides a powerful tool for in-situ tuning of the band structure such that all trivial pockets are pushed far away from the Fermi energy, but only for a certain range of Van der Waals gaps. Our results naturally reconcile contradicting reports on the presence or absence of additional pockets in ZrTe5, and provide a clear map of where to find a pure three-dimensional Dirac semimetallic phase in the structural parameter space of the material.
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| 3. |
- Marlton, Frederick, et al.
(author)
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A simple correction for the parallax effect in X-ray pair distribution function measurements
- 2019
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In: Journal of Applied Crystallography. - 0021-8898. ; 52, s. 1072-1076
-
Journal article (peer-reviewed)abstract
- Total scattering and pair distribution function (PDF) analysis has created new insights that traditional powder diffraction methods have been unable to achieve in understanding the local structures of materials exhibiting disorder or complex nanostructures. Care must be taken in such analyses as subtle and discrete features in the PDF can easily be artefacts generated in the measurement process, which can result in unphysical models and interpretation. The focus of this study is an artefact called the parallax effect, which can occur in area detectors with thick detection layers during the collection of X-ray PDF data. This effect results in high-Q peak offsets, which subsequently cause an r-dependent shift in the PDF peak positions in real space. Such effects should be accounted for if a truly accurate model is to be achieved, and a simple correction that can be conducted via a Rietveld refinement against the reference data is proposed.
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| 4. |
- Nocerino, Elisabetta, et al.
(author)
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Structural Evolution and Onset of the Density Wave Transition in the CDW Superconductor LaPt2Si2 Clarified with Synchrotron XRD
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Other publication (other academic/artistic)abstract
- The quasi-2D Pt-based rare earth intermetallic material LaPt2Si2 has attracted attention as it exhibits strong interplay between charge density wave (CDW) and and superconductivity (SC). However, the most of the results reported on this material come from theoretical calculations, preliminary bulk investigations and powder samples, which makes it difficult to uniquely determine the temperature evolution of its crystal structure and, consequently, of its CDW transition. Therefore, the published literature around LaPt2Si2 is often controversial. In this paper, we clarify the complex evolution of the crystal structure, and the temperature dependence of the development of density wave transitions, in good quality LaPt2Si2 single crystals, with high resolution synchrotron X-ray diffraction data. According to our findings, on cooling from room temperature LaPt2Si2 undergoes a series of subtle structural transitions which can be summarised as follows: second order commensurate tetragonal (P4/nmm)-to-incommensurate structure followed by a first order incommensurate-to-commensurate orthorhombic (Pmmn) transition and then a first order commensurate orthorhombic (Pmmn)-to-commensurate tetragonal (P4/nmm). The structural transitions are accompanied by both incommensurate and commensurate superstructural distortions of the lattice. The observed behavior is compatible with discommensuration of the CDW in this material.
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