Search results for "layer"

Vapor phase epitaxy of Hg1−xCdxI2 layers on CdTe substrates

1997

Vapor phase epitaxy (VPE) has been studied to grow Hg1 − xCdxI2 epitaxial layers on CdTe bulk substrates. The effect of the VPE growth conditions on the morphology, composition and crystalline quality of Hg1 − xCdxI2CdTe heterostructures has been investigated. It has been shown that 10–30 μm thick Hg1 − xCdxI2 layers can be successfully grown using an α-HgI2 polycrystalline source under isothermal conditions at a temperature in the range 170–240°C for the time period 20–50 h. Interestingly, the VPE growth was found to consist of two successiv stages with different kinetics as follows: (1) a fast growth of an HgI2 platelet layer on the CdTe substrate surface and (2) a slow growth of an Hg1 −…

Influence of morphology in the magnetic properties of layered double hydroxides

2018

We report the controlled synthesis of magnetic CoAl and NiFe layered double hydroxides (LDHs) endowed with well-defined morphology (hexagonal and flower-like shapes) by means of modified homogeneous precipitation. These layered magnets display high crystallinity and micrometric size, thus offering a perfect scenario for the elucidation of the role exerted by distortion of the layers in their magnetic behaviour. The magnetic properties have been investigated by means of DC and AC magnetic susceptibility measurements and isothermal magnetization, demonstrating that the distortion of the nanosheets induces a magnetically more disordered behaviour, with marked spin-glass nature, independently o…

Identification of Synaptic Integration Mode in CA3 Pyramidal Neuron Model

2019

International audience; A morphologically realistic and anisotropic model of CA3 pyramidal neuron was developed to determine the synaptic integration modes the neuron is able to perform. Linearity and nonlinearity were identified in different synaptic locations with varying active mechanisms such as the presence of ionic channels in the dendritic arbor and the types of receptors in the synapse. Quantification of synaptic integration was performed using paired-pulse stimulation protocol and subthreshold input/output (sI/O) transformation. Results show that the mode of synaptic integration is location-dependent while the linearity or nonlinearity in the integration is mainly influenced by the…

Mott-Schottky analysis of differential capacitance data of passive-film electrolyte junctions. Is it really providing correct physical insights on th…

2009

Risks of condensate formation and mould growth in buildings under Latvian climate conditions

2013

Des traces archéologiques témoins de l’implantation d’un vignoble sur le finage de Cernay-lès-Reims et Saint-Léonard au Moyen Âge

2019

Thanks to the numerous archaeological operations carried out in Cernay-lès-Reims and Saint-Léonard - on the south-eastern edge of the Reims urban area - several sites from protohistory to the contemporary period were discovered. Among them, the presence of a multitude of small trapezoidal pits could be observed, and that over a large part of the area that was the subject of the interventions. With their atypical shapes, these pits are the proof of a wine-growing activity at the edge of Cernay-lès-Reims around the 11th-13th centuries.

Studying Nucleosomes Positioning by a Multi-Layer Model

2007

Eukaryotic DNA is packaged into a highly compact and dynamic structure called chromatin. While this packaging allows the cell to organize a large and complex genome in the nucleus, it can also block the access of transcription factors and other proteins to DNA. Nucleosomes are the fundamental repeating units of eukaryotic chromatin. Nucleosome position can be regulated in vivo by multi-subunit chromatin remodeling complexes, and their position can influence gene expression in eukaryotic cells. Alterations in chromatin structure, and hence in nucleosome organization, can result in a variety of diseases, including cancer, highlighting the need to achieve a better understanding of the molecula…

2015

AbstractWhile understanding the properties of materials under stress is fundamentally important, designing experiments to probe the effects of large tensile stress is difficult. Here tensile stress is created in thin films of potassium (up to 4 atomic layers) by epitaxial growth on a rigid support, graphite. We find that this “simple” metal shows a long-range, periodic “herringbone” reconstruction, observed in 2- and 3- (but not 1- and 4-) layer films by low-temperature scanning tunneling microscopy (STM). Such a pattern has never been observed in a simple metal. Density functional theory (DFT)simulations indicate that the reconstruction consists of self-aligned stripes of enhanced atom den…

Experimental and theoretical evidence for bilayer-by-bilayer surface melting of crystalline ice

2017

On the surface of water ice, a quasi-liquid layer (QLL) has been extensively reported at temperatures below its bulk melting point at 273 K. Approaching the bulk melting temperature from below, the thickness of the QLL is known to increase. To elucidate the precise temperature variation of the QLL, and its nature, we investigate the surface melting of hexagonal ice by combining noncontact, surface-specific vibrational sum frequency generation (SFG) spectroscopy and spectra calculated from molecular dynamics simulations. Using SFG, we probe the outermost water layers of distinct single crystalline ice faces at different temperatures. For the basal face, a stepwise, sudden weakening of the hy…

Coexistence of structural and magnetic phases in van der Waals magnet CrI3

2021

CrI3 has raised as an important system to the emergent field of two-dimensional van der Waals magnetic materials. However, it is still unclear why CrI3 which has a ferromagnetic rhombohedral structure in bulk, changed to anti-ferromagnetic monoclinic at thin layers. Here we show that this behaviour is due to the coexistence of both monoclinic and rhombohedral crystal phases followed by three magnetic transitions at TC1 = 61 K, TC2 = 50 K and TC3 = 25 K. Each transition corresponds to a certain fraction of the magnetically ordered volume as well as monoclinic and rhombohedral proportion. The different phases are continuously accessed as a function of the temperature over a broad range of mag…