Combining Research and Education to Advance Okayama University: Innovative Strategies to Return onto the Road of Success

For many years, there have been numerous attempts by the Japanese Government (MEXT in particular) to help Japanese Universities to keep pace with their counterparts in international developed nations. In 2020, only 3 of them remain in the top 100 of the ARWU list, and the ranking of Japanese universities continues to be significantly on decline. Based on the well-known Humboldt model, putting research at the core of the system, an innovative development strategy has been implemented at Okayama University. The paper details the major features of the method and finally concludes on the possible extension of the model to numerous Japanese universities where research teams are significantly present

Advances in Superconductivity as a road to meet Energy and Health SDGs: joint Japanese and European research teams may take the lead

Based on a statistical analysis of R&D activities in the field of superconductivity (SC) in a broad sense, the paper reports that Japan's leadership is strong over the past 20 years, in terms of researchers publications and patents. It also essentially shows that among the main world players, the Japanese normalized contribution is significantly dominating, although some trend towards a diminished leadership is observed in the data over the period 2005 -present time. Finally, the paper highlights that by taking advantage of their internationally recognized expertise in the field, joint Japanese and European research teams may advance superconductivity as a reliable road to meet Energy and Health SDGs (Sustainable Development Goals -UNESCO 2015)

Strain mapping at the nanoscale using precession electron diffraction in transmission electron microscope with off axis camera

International audiencePrecession electron diffraction is an efficient technique to measure strain in nanostructures by precessing the electron beam, while maintaining a few nanometre probe size. Here, we show that an advanced diffraction pattern treatment allows reproducible and precise strain measurements to be obtained using a default 512 x 512 DigiSTAR off-axis camera both in advanced or non-corrected transmission electron microscopes. This treatment consists in both projective geometry correction of diffraction pattern distortions and strain Delaunay triangulation based analysis. Precision in the strain measurement is improved and reached 2.7 x 10(-4) with a probe size approaching 4.2 nm in diameter. This method is applied to the study of the strain state in InGaAs quantum-well (QW) devices elaborated on Si substrate. Results show that the GaAs/Si mismatch does not induce in-plane strain fluctuations in the InGaAs QW region. (C) 2014 AIP Publishing LLC

Caractérisation et développement d'architectures 3 D pour capacités métal-isolant-métal intégrant des électrodes en cuivre et des diélectriques à permittivité élevée

GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Elaboration de grilles à base de matériau metallique pour des filières CMOS avancées

Ce travail de thèse s'est concentré sur la sélection, la mise en œuvre et la caractérisation de matériaux en films minces pour une utilisation en tant que grille métallique dans les transistors MOS de génération sub-45nm. Dans un premier temps, une analyse bibliographique approfondie a permis de préciser les paramètres physico-chimiques essentiels à maîtriser pour obtenir une électrode de grille adaptée c'est à dire un matériau dont le travail de sortie puisse être adapté pour servir soit d'électrode n ou p. Cette synthèse analyse détaillée a conduit au choix du nitrure de titane TiN, déposé à partir d'un précurseur organométallique par deux méthodes (MOCVD et MOALD). Des essais de modulation du travail de sortie ont été réalisés en utilisant des traitements pendant ou après le dépôt : Pour tirer partie de l'anisotropie du travail de sortie du TiN, un traitement plasma qui permet d'adapter l'orientation préférentielle des nano cristallites dans les films a été étudié. Cependant, lorsqu'il est appliqué sur l'interface TiN/diélectrique, le diélectrique s'en retrouve dégradé. Pour tirer partie de l'influence de la nature chimique du TiN sur le travail de sortie, l'insertion de silicium dans le matériau de grille a été étudiée. L'incorporation maîtrisée de Si dans la couche mince de TiN permet de contrôler de manière précise le travail de sortie.Les diverses couches obtenues ont été caractérisées physiquement (composition, nature des liaisons chimiques, morphologie, texture ...) et électriquement (travail de sortie, impact sur les diélectriques sous-jacents). L'évolution de ces propriétés avec la température est étudiée.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Anisotropy of thermal expansion in YAlO3 and NdGaO3

3 pagesInternational audienceYAlO3 and NdGaO3 thermal expansion coefficients were measured using in-situ powder X-ray diffraction in the temperature range 28-650°C. They exhibit a clear anisotropy: the expansion, quite similar along the [100] and [001] directions, is much lower along the [010] direction. The formation of cracks observed in YBa2Cu3O7-d thin films deposited on YAlO3 and NdGaO3 substrates is likely related to the anisotropy. Stress value calculations have been performed in both systems. They indicate the intrinsic components are specifically high in YAlO3

Work Function Tuning of TixSiyNz Electrodes Using Partial Saturation of Chemisorbing Surface during Pulsing Chemical Vapor Deposition

International audienceIn this article, the achievement of TixSiyNz metal gates with tunable work function is demonstrated using partial saturation during pulsing chemical vapor deposition. Thin films were deposited on SiO2 using a pulse sequence with tetrakisdimethyl amido titanium, NH3, and SiH4 precursors. By adjusting the silane pulse, the chemisorption kinetics of silane on the surface is finely tuned to control the composition of TixSiyNz layers. Their effective work functions were measured in metal-oxide-semiconductor capacitors. Results indicate that the effective work function can be accurately monitored in the range of 4.35-4.60 eV by adjusting the silane pulse time

Second order incommensurate phase transition in 25L-Ta2O5

International audienceA new structural state 25L-Ta2O5, obtained from sintering and annealing treatments of a Ta2O5 powder, is identified both by electron diffraction and high resolution imaging on a transmission electron microscope (TEM). According to general rules for the different L-Ta2O5 structures proposed by Grey et al. (J. Solid State Chem. 178 (2005) 3308), a structural model is derived from their crystallographic data on 19L-Ta2O5. This model yields simulated images in agreement with high resolution TEM observations of the structure oriented along its [001] zone axis, but only for a very thin crystal thickness of less than 1.2 nm. Such a limitation is shown to be due to a modulation of the structure along its [001] axis. Actually, from an analysis of a diffuse scattering and of its evolution into satellites reflections as a function of the cooling rate, a second order incommensurate phase transition can be assumed to occur in this compound. The property of single phase samples observed by TEM is also verified by X-ray powder diffraction. In a discussion about studies performed by different authors on incommensurate structures in the system Ta2O5-WO3, it is noticed that TEM results, similar to ours, indicate that phase transitions could be expected in these structures. (C) 2010 Elsevier Inc. All rights reserved