Journal: Nanoscale Horizons

Abbreviation

Nanoscale Horiz

Publisher

Royal Society of Chemistry

Journal Volumes

ISSN

2055-6756
2055-6764

Description

Filters

2016 - 201932020 - 20244
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Publications 1 - 7 of 7
  • Dually actuated atomic force microscope with miniaturized magnetic bead-actuators for single-molecule force measurements
    Item type: Journal Article
    Sevim, Semih; Ozer, Sevil; Feng, Luying; et al. (2016)
    Nanoscale Horizons
  • Control of Ge island coalescence for the formation of nanowires on silicon
    Item type: Journal Article
    Ramanandan, Santhanu Panikar; Sapera, Joel Reñé; Morelle, Alban; et al. (2024)
    Nanoscale Horizons
    Germanium nanowires could be the building blocks of hole-spin qubit quantum computers. Selective area epitaxy enables the direct integration of Ge nanowires on a silicon chip while controlling the device design, density, and scalability. For this to become a reality, it is essential to understand and control the initial stages of the epitaxy process. In this work, we highlight the importance of surface treatment in the reactor prior to growth to achieve high crystal quality and connected Ge nanowire structures. In particular, we demonstrate that exposure to AsH₃ during the high-temperature treatment enhances lateral growth of initial Ge islands and promotes faster formation of continuous Ge nanowires in trenches. The Kolmogorov-Johnson-Mehl-Avrami crystallization model supports our explanation of Ge coalescence. These results provide critical insight into the selective epitaxy of horizontal Ge nanowires on lattice-mismatched Si substrates, which can be translated to other material systems.
  • Lipid-based mesophases as matrices for nanoscale reactions
    Item type: Journal Article
    Salvati Manni, Livia; Fong, Wye-Khay; Mezzenga, Raffaele (2020)
    Nanoscale Horizons
  • Metal assisted chemical etching of silicon in the gas phase: a nanofabrication platform for X-ray optics
    Item type: Journal Article
    Romano, Lucia; Kagias, Matias; Vila-Comamala, Joan; et al. (2020)
    Nanoscale Horizons
    High aspect ratio nanostructuring requires high precision pattern transfer with highly directional etching. In this work, we demonstrate the fabrication of structures with ultra-high aspect ratios (up to 10 000 : 1) in the nanoscale regime (down to 10 nm) by platinum assisted chemical etching of silicon in the gas phase. The etching gas is created by a vapour of water diluted hydrofluoric acid and a continuous air flow, which works both as an oxidizer and as a gas carrier for reactive species. The high reactivity of platinum as a catalyst and the formation of platinum silicide to improve the stability of the catalyst pattern allow a controlled etching. The method has been successfully applied to produce straight nanowires with section size in the range of 10–100 nm and length of hundreds of micrometres, and X-ray optical elements with feature sizes down to 10 nm and etching depth in the range of tens of micrometres. This work opens the possibility of a low cost etching method for stiction-sensitive nanostructures and a large range of applications where silicon high aspect ratio nanostructures and high precision of pattern transfer are required.
  • Synthesis of aerogels: from molecular routes to 3-dimensional nanoparticle assembly
    Item type: Journal Article
    Rechberger, Felix; Niederberger, Markus (2017)
    Nanoscale Horizons
  • Direct observation of spin correlations in an artificial triangular lattice Ising spin system with grazing-incidence small-angle neutron scattering
    Item type: Journal Article
    Pip, Petai; Glavic, Artur; Skjærvø, Sandra H.; et al. (2021)
    Nanoscale Horizons
    The triangular lattice with Ising magnetic moments is an archetypical example of geometric frustration. In the case of dipolar-coupled out-of-plane moments, the geometric frustration results in a disordered classical spin-liquid state at higher temperatures while the system is predicted to transition to an anti-ferromagnetic stripe ground state at low temperatures. In this work we fabricate artificial triangular Ising spin systems without and with uniaxial in-plane compression to tune the nature and temperature of the correlations. We probe the energy scale and nature of magnetic correlations by grazing-incidence small-angle neutron scattering. In particular, we apply a newly-developed empirical structure-factor model to describe the measured short-range correlated spin-liquid state, and find good agreement with theoretical predictions. We demonstrate that grazing-incidence neutron scattering on our high-quality samples, in conjunction with detailed modeling of the scattering using the Distorted Wave Born Approximation, can be used to experimentally quantify the spin-liquid-like correlations in highly-frustrated artificial spin systems.
  • Ultrafast rotational motions of supported nanoclusters probed by electron diffraction
    Item type: Journal Article
    Vasileiadis, Thomas; Skountzos, Emmanuel N.; Foster, Dawn; et al. (2019)
    Nanoscale Horizons
    In crystals, microscopic energy flow is governed by electronic and vibrational excitations. In nanoscale materials, however, translations and rotations of entire nanoparticles represent additional fundamental excitations. The observation of such motions is elusive as most ultrafast techniques are insensitive to motions of the phonons’ frame of reference. Here, we study heterostructures of size-selected Au nanoclusters with partial (111) orientation on few-layer graphite with femtosecond electron diffraction. We demonstrate that ultrafast, constrained rotations of nanoclusters, so-called librations, in photo-induced non-equilibrium conditions can be observed separately from vibrational structural dynamics. Molecular dynamics and electron diffraction simulations provide quantitative understanding on librations-induced deviations from the conventional temperature dependence of diffraction patterns. We find that nanocluster librations with a period of ∼20 picoseconds are triggered quasi-impulsively by graphene flexural motions. These ultrafast structural dynamics modulate the Au/C interface and hence are expected to play a key role in energy- and mass-transport at the nanoscale.
Publications 1 - 7 of 7