Chirality-mediated bistability and strong frequency downshifting of the gyrotropic resonance of a dynamically de-stiffened magnetic vortex

We demonstrate an enhanced, bidirectional, in-plane magnetic field tuning of the gyrotropic resonance frequency of a magnetic vortex within a disk by introducing a flat edge. When the core is in its vicinity, the flat edge locally reduces the core's directional dynamic stiffness for movement parallel to the edge. This strongly reduces the net dynamic core stiffness, leading to the gyrotropic frequency being significantly less than when the core is centered (or located near the round edge). This leads to the measurable range of gyrotropic frequencies being more than doubled and also results in a clear chirality-mediated bistability of the gyrotropic resonance frequency due to what is effectively a chirality-dependence of the core's confining potential.Comment: 6 pages, 5 figure

REPRESENTAÇÕES DO BRASIL E DO BRASILEIRO NO DISCURSO DO JORNAL ESPANHOL EL PAÍS NO CONTEXTO PRÉ-COPA FIFA DE 2014

A produção de discursos da mídia internacional sobre o cenário político do Brasil esteve em efervescência nos últimos anos devido aos diversos megaeventos esportivos sediados no país, desde a Copa das Confederações, em 2013, e da Copa do Mundo, em 2014, até os Jogos Olímpicos, em 2016, os quais proporcionaram grande visibilidade ao país no exterior. Este trabalho objetiva analisar artigos de opinião do jornal espanhol El País, veiculados entre 2013 e 2014, a fim de observar as estruturas discursivas presentes quanto às representações e estereótipos do Brasil e do brasileiro no contexto das manifestações políticas daquele período. Para tanto, utilizaremos os pressupostos da Análise Crítica do Discurso (ACD), especialmente os trabalhos de Van Dijk (2008; 2012), em diálogo com estudiosos das Ciências Sociais (BOURDIEU, 1989), da Psicologia Social (MOSCOVICI, 1978; 2004), dos Estudos Culturais (HALL, 2000; 2011) e demais autores que contribuíram para a constituição de um panorama sócio-histórico do Brasil (ZWEIG, 2013; AGASSIZ, 1975; RAEDERS, 1988) etc., o que caracteriza um viés multidisciplinar a partir da Linguística. Encontramos na Análise Crítica do Discurso (ACD) nossa abordagem, uma vez que, enquanto perspectiva crítica que tem por finalidade principal o exame das relações entre discurso e poder, esta nos permitirá indagar uma possível polarização intergrupal entre europeus e brasileiros e a consequente (re) produção de representações desfavoráveis do Brasil e do brasileiro e a existência de uma relação hierarquizada entre culturas, a partir do discurso jornalístico espanhol

Multilayer encapsulation using Atomic Layer Deposition and a moisture- stable silica containing nanocomposite polymer: correlation between gas permeation measurement on plastic film and performances obtained on top-emitting Organic Light-Emitting Diodes

Abstract Thin Film Encapsulation (TFE) using a multilayer stack of inorganic and organic films is now a well-known encapsulation technology for organic electronics such as Organic Light-Emitting Diodes (OLED). It shows excellent gas barrier properties with very low WVTR, and good compatibility with flexible and transparent substrates. In this study, low-temperature Atomic Layer Deposition (ALD) serves for the fabrication of high performance Al2O3 inorganic barrier layers. A silica nanocomposite polymer serves as a moisture-stable interface layer in a very high barrier quality architecture of the kind [Al2O3 (25 nm)/nano-CP (1 µm)/Al2O3 (25 nm)/nano-CP (5 µm)]. The helium and water vapor quantitative gas permeation properties (HeTR and WVTR) of different intermediate TFE architectures deposited on plastic substrate (PET) are analyzed using a permeameter. These results are compared to an accelerated weathering test standard, for monolithic TFE deposited in-situ on top-emitting OLED circuits. On PET, the best TFE stack decreases the steady state permeation rate by a factor 1180 and 1650 respectively for helium and water vapor. Onto a top-emitting OLED, the long-term black spot occurrence rate drastically decreased from 100 %.h− 1 to 3.210− 3 %.h− 1, attesting the successful implementation of this TFE architecture from ex-situ on PET substrate to in-situ on OLED circuits.</jats:p

Module reliability: lessons learned for a smart tandem integration

International audienceModule reliability: lessons learned for a smart tandem integrationPresentation au tandemPV workshop en remplacement Ulrike Jahn: talk invit

Module reliability: lessons learned for a smart tandem integration

International audienceModule reliability: lessons learned for a smart tandem integrationPresentation au tandemPV workshop en remplacement Ulrike Jahn: talk invit

ALD-grown SnO2_2 as an electron selective layer for perovskite/silicon tandem cells

International audienceThis work presents a comparative study between tin(IV) oxide (SnO2) thin films deposited either by solution process or by Atomic Layer Deposition (ALD) for an application as an electron selective layer in perovskite/silicon tandem solar cells. This study is motivated by the usually lower performances of electron selective layers made of ALD-grown SnO2 compared to ones made via solution processes. Chemical, electrical, optical and topographical properties of each type of film were investigated. In an attempt to link thin film properties to device characteristics single-junction perovskite solar cells and perovskite/silicon tandem solar cells were fabricated. Despite the high-quality electronic and optical properties of ALD-grown SnO2, perovskite-based solar cells employing such film showed limited performances. Characterization of perovskite films properties grown on both type of SnO2 did not rise significant differences and tend to indicate some hindering factors at the ALD-grown SnO2 interface with perovskite. Specifically, Kelvin force probe microscopy characterisation unveiled a larger workfunction for ALD-grown SnO2, which may create a potential barrier for electron extraction from the perovskite