![]() Sharma, Anjali ![]() ![]() in Journal of Applied Physics (2021), 129(17), 174701 We produce hollow sphere liquid crystal elastomer (LCE) actuators from a nematic precursor mixture, brought into the shape of a self-closing shell with tangential anchoring of the director field n(r ... [more ▼] We produce hollow sphere liquid crystal elastomer (LCE) actuators from a nematic precursor mixture, brought into the shape of a self-closing shell with tangential anchoring of the director field n(r), using a solvent-assisted microfluidic technique. By separating the shell production from the polymerization and cross-linking, the precursor is allowed to approach its equilibrium n(r) configuration in the shell, spontaneously forming topological defects of total strength +2. However, the photopolymerization into an LCE induces a brief but strong distortion of the overall n(r) and the defect configuration, even changing the ground state shape in the case of thick shells. The resulting LCE shells show a rich capacity for reversible shape morphing upon heating and cooling, the exact actuation mode defined by n(r), and the final defect configuration stabilized at the end of polymerization. In regions with a single +1 defect, a reversal of curvature from concave to convex is found, punctured shells exhibit a strong shape change between a nearly closed sphere at low temperature and an open-ended spherocylinder at high temperature, and all shells rotate upon actuation when suspended in a fluid. As the rotation is stronger during relaxation than during actuation, thus breaking the symmetry, the net rotation is unidirectional. [less ▲] Detailed reference viewed: 55 (1 UL)![]() ; Hasdeo, Eddwi Hesky ![]() in Journal of Applied Physics (2021), 129(1), 014306 The Dirac nodal-line semimetals are new promising materials for technological applications due to their exotic properties, which originate from band structure dispersion and nodal-line behavior. We report ... [more ▼] The Dirac nodal-line semimetals are new promising materials for technological applications due to their exotic properties, which originate from band structure dispersion and nodal-line behavior. We report strain effects on the band structure of ZrSiSe Dirac nodal-line semimetal through the density functional theory calculations. We found that the kz=0 Dirac nodal-line of ZrSiSe is robust to all strains under reasonable magnitude although there are significant changes in the band oscillation amplitude, bandgap, and band occupancy due to orbital interactions and the Fermi energy shift upon strains. We also found that the effective strains to tune the nodal-line and band structure are equi-biaxial tensile, uniaxial (100) tensile, and xz-plane shear strains. [less ▲] Detailed reference viewed: 102 (1 UL)![]() ; ; et al in Journal of Applied Physics (2021), 130 Magnetic nanostructures sustaining different types of optical modes have been used for magnetometry and label-free ultrasensitive refractive index probing, where the main challenge is the realization of ... [more ▼] Magnetic nanostructures sustaining different types of optical modes have been used for magnetometry and label-free ultrasensitive refractive index probing, where the main challenge is the realization of compact devices that are able to transfer this technology from research laboratories to smart industry. This Perspective discusses the state-of-the-art and emerging trends in realizing innovative sensors containing new architectures and materials exploiting the unique ability to actively manipulate their optical properties using an externally applied magnetic field. In addition to the well-established use of propagating and localized plasmonic fields, in the so-called magnetoplasmonics, we identified a new potential of the all-dielectric platforms for sensing to overcome losses inherent to metallic components. In describing recent advances, emphasis is placed on several feasible industrial applications, trying to give our vision on the future of this promising field of research merging optics, magnetism, and nanotechnology. [less ▲] Detailed reference viewed: 29 (1 UL)![]() Maccaferri, Nicolò ![]() in Journal of Applied Physics (2020), 127(8), 080903 This Perspective surveys the state-of-the-art and future prospects of science and technology employing nanoconfined light (nanophotonics and nanoplasmonics) in combination with magnetism. We denote this ... [more ▼] This Perspective surveys the state-of-the-art and future prospects of science and technology employing nanoconfined light (nanophotonics and nanoplasmonics) in combination with magnetism. We denote this field broadly as nanoscale magnetophotonics. We include a general introduction to the field and describe the emerging magneto-optical effects in magnetoplasmonic and magnetophotonic nanostructures supporting localized and propagating plasmons. Special attention is given to magnetoplasmonic crystals with transverse magnetization and the associated nanophotonic non-reciprocal effects and to magneto-optical effects in periodic arrays of nanostructures. We also give an overview of the applications of these systems in biological and chemical sensing, as well as in light polarization and phase control. We further review the area of nonlinear magnetophotonics, the semiconductor spin-plasmonics, and the general principles and applications of opto-magnetism and nano-optical ultrafast control of magnetism and spintronics. [less ▲] Detailed reference viewed: 176 (7 UL)![]() Spindler, Conrad ![]() ![]() ![]() in Journal of Applied Physics (2019) Detailed reference viewed: 157 (14 UL)![]() ; ; Kreisel, Jens ![]() in JOURNAL OF APPLIED PHYSICS (2019), 126(16), The pressure dependence of light-induced effects in single-crystalline BiFeO3 is studied by optical spectroscopy. At low pressures, we observe three light-induced absorption features with energies just ... [more ▼] The pressure dependence of light-induced effects in single-crystalline BiFeO3 is studied by optical spectroscopy. At low pressures, we observe three light-induced absorption features with energies just below the two crystal-field excitations and the absorption onset, respectively. These absorption features were previously ascribed to excitons, possibly connected with the ultrafast photostriction effect in BiFeO3. The pressure-induced redshift of the absorption features follows the pressure dependence of the corresponding crystal-field excitations and absorption onset, suggesting the link between them. Above the structural phase transition at P-c1 approximate to 3.5 GPa, the three absorption features disappear, suggesting their connection to the polar phase in BiFeO3. The pressure-induced disappearance of the photoinduced features is irreversible upon pressure release. Published under license by AIP Publishing. [less ▲] Detailed reference viewed: 75 (2 UL)![]() ; ; Kreisel, Jens ![]() in JOURNAL OF APPLIED PHYSICS (2019), 125(11), We studied the light-induced effects in BiFeO3 single crystals as a function of temperature by means of optical spectroscopy. Here, we report the observation of several light-induced absorption features ... [more ▼] We studied the light-induced effects in BiFeO3 single crystals as a function of temperature by means of optical spectroscopy. Here, we report the observation of several light-induced absorption features which are discussed in terms of the photostriction effect and are interpreted in terms of excitons. The temperature dependence of their energy position suggests a possible coupling between the excitons and the lattice vibrations. Moreover, there are hints for anomalies in the temperature evolution of the excitonic features, which might be related to the temperature-induced magnetic phase transitions in BiFeO3. Our findings suggest a coupling between light-induced excitons and the lattice and spin degrees of freedom, which might be relevant for the observed ultrafast photostriction effect in multiferroic BiFeO3. Published under license by AIP Publishing. [less ▲] Detailed reference viewed: 120 (2 UL)![]() Werner, Florian ![]() in Journal of Applied Physics (2017), 122 Detailed reference viewed: 193 (5 UL)![]() ; ; Moors, Kristof ![]() in Journal of Applied Physics (2017), 122(2), We report on the thin film resistivity of several platinum-group metals (Ru, Pd, Ir, and Pt). Platinum-group thin films show comparable or lower resistivities than Cu for film thicknesses below about 5 nm ... [more ▼] We report on the thin film resistivity of several platinum-group metals (Ru, Pd, Ir, and Pt). Platinum-group thin films show comparable or lower resistivities than Cu for film thicknesses below about 5 nm due to a weaker thickness dependence of the resistivity. Based on experimentally determined mean linear distances between grain boundaries as well as ab initio calculations of the electron mean free path, the data for Ru, Ir, and Cu were modeled within the semiclassical Mayadas-Shatzkes model [Phys. Rev. B 1, 1382 (1970)] to assess the combined contributions of surface and grain boundary scattering to the resistivity. For Ru, the modeling results indicated that surface scattering was strongly dependent on the surrounding material with nearly specular scattering at interfaces with SiO2 or air but with diffuse scattering at interfaces with TaN. The dependence of the thin film resistivity on the mean free path is also discussed within the Mayadas-Shatzkes model in consideration of the experimental findings. [less ▲] Detailed reference viewed: 245 (1 UL)![]() Weiss, Thomas ![]() ![]() ![]() in Journal of Applied Physics (2016), 120 Detailed reference viewed: 214 (10 UL)![]() Werner, Florian ![]() ![]() ![]() in JOURNAL OF APPLIED PHYSICS (2016), 119 Detailed reference viewed: 241 (18 UL)![]() ; Redinger, Alex ![]() in JOURNAL OF APPLIED PHYSICS (2016), 120(17), Intragrain charge carrier mobilities measured by time-resolved terahertz spectroscopy in state of the art Cu2ZnSn(S,Se)(4) kesterite thin films are found to increase from 32 to 140 cm(2) V-1 s(-1) with ... [more ▼] Intragrain charge carrier mobilities measured by time-resolved terahertz spectroscopy in state of the art Cu2ZnSn(S,Se)(4) kesterite thin films are found to increase from 32 to 140 cm(2) V-1 s(-1) with increasing Se content. The mobilities are limited by carrier localization on the nanometer-scale, which takes place within the first 2 ps after carrier excitation. The localization strength obtained from the Drude-Smith model is found to be independent of the excited photocarrier density. This is in accordance with bandgap fluctuations as a cause of the localized transport. Charge carrier localization is a general issue in the probed kesterite thin films, which were deposited by co-evaporation colloidal inks, and sputtering followed by annealing with varying Se/S contents and yield 4.9\%-10.0 efficiency in the completed device. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). [less ▲] Detailed reference viewed: 103 (1 UL)![]() Sendler, Jan ![]() ![]() ![]() in Journal of Applied Physics (2016), 120 Detailed reference viewed: 255 (6 UL)![]() ; ; et al in Journal of Applied Physics (2015), 117 Detailed reference viewed: 157 (11 UL)![]() ; ; et al in Journal of Applied Physics (2015), 118 Detailed reference viewed: 211 (7 UL)![]() Hönes, Christian ![]() in Journal of Applied Physics (2015), 117 Detailed reference viewed: 193 (6 UL)![]() ; Redinger, Alex ![]() in JOURNAL OF APPLIED PHYSICS (2015), 118(8), Detailed reference viewed: 85 (1 UL)![]() ; Mousel, Marina ![]() ![]() in JOURNAL OF APPLIED PHYSICS (2015), 118 Detailed reference viewed: 226 (6 UL)![]() Depredurand, Valérie ![]() ![]() in JOURNAL OF APPLIED PHYSICS (2014), 115 Detailed reference viewed: 309 (11 UL)![]() Luckas, Jennifer Maria ![]() ![]() in JOURNAL OF APPLIED PHYSICS (2014), 116 Detailed reference viewed: 176 (2 UL) |
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