A. Rougier - Academia.edu (original) (raw)

Papers by A. Rougier

ACS Applied Materials & Interfaces, 2019

Novel design of electrochromic devices ECDs, known for their ability to modify their optical prop... more Novel design of electrochromic devices ECDs, known for their ability to modify their optical properties under an applied voltage, based on a minimization of the number of layers is reported. The use of a metallic electrode, playing the role of both the conductive layer as well as the counter electrode allows to simplify the assembly of commonly 5 layers battery type device to 4-layers ECD. Further minimization of the number of layers is achieved by using a conductive and electrochromic material. The novelty of the device configuration is illustrated using poly(3,4-ethylenedioxythiophene) PEDOT based materials as EC layer, lithium based ionic liquid as electrolyte and Ag as counter electrode. Such 4-or 3-layer ECD deposited on paper substrate switches from light to deep blue in a narrow 0.7 V voltage window. Preliminary investigations of the mechanism indicate traces of Ag on the PEDOT layer upon cycling. Finally, the printed ECD is successfully activated using a mobile phone.

The Journal of Physical Chemistry B, 2005

The oxygen vacancy in WO(3) has previously been implicated in the electrochromism mechanism in th... more The oxygen vacancy in WO(3) has previously been implicated in the electrochromism mechanism in this material. Previous theoretical calculations on the oxygen vacancy in WO(3) have not considered the full range of crystal structures adopted by the material. Here we report studies of the oxygen vacancy in seven crystal phases. The use of a very accurate tungsten plane-wave pseudopotential means that a byproduct of this study is a more detailed and complete picture of undefected WO(3) than previously available. Electronic structures of the crystal phases in both undefected and defected systems have been calculated and are discussed. The band gap in WO(3) is dependent upon bonding-antibonding interactions, these being dependent upon overlap in each direction. The effect of an oxygen vacancy is dependent upon the availability of both Op and Wd electrons, this being different for the various phases. A variety of behavior is predicted, which may be explained in terms of O2p-W5d mixing, including the formation of long W-W dimer bonds. It is found that the nature of a polaron in this material is dependent upon both the crystal structure and distribution of oxygen vacancies.

Powder Technology, 2002

The influence of grinding on the structure and catalytic performances of two families of oxides, ... more The influence of grinding on the structure and catalytic performances of two families of oxides, namely the perovskite-type La 0.8 Sr 0.2 MnO 3 F k and the spinel-type Li-Mn-O, was investigated. Ball-milling of the well-known La 0.8 Sr 0.2 MnO 3 F k prepared either by a solid state reaction or by a sol-gel method led to (i) a decrease in carbon black combustion temperature of 100 jC (T C = 540 jC) and of 40 jC (T C = 505 jC) for ceramic and sol-gel ground 5-h samples, respectively, and (ii) to faster kinetics and higher rates of toluene conversion. A greater enhancement of the catalytic performances was obtained by using mechanical milled lithiated manganese oxides that are reported as promising catalyst candidates for the first time. Li-Mn-O catalysts were synthesized by room temperature mechanochemistry of a stoichiometric mixture of Li 2 O and MnO 2 using various milling times (0 < t milling < 15 h). The nonstoichiometry, large surface area and disorder nature of the ground samples were of great benefit regarding catalytic applications. A remarkable decrease in the carbon black combustion temperature of 200 jC (from 650 to 450 jC) was obtained when using a mixture of Li 2 O and MnO 2 ground for 3 or 4 h. This low T C value favorably compares with the T C of 500 jC of ceramic LiMn 2 O 4 , which shows, however, better catalytic performances than most of the perovskite-type oxides. The grinding proves to be efficient as well for volatile organic compounds (VOCs) combustion. The inactive ceramic LiMn 2 O 4 exhibits a 100% toluene conversion rate for a temperature lower than 200 jC when ground 5 h.

Thin Solid Films, 2006

Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny met... more Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny metallic to transparent states were observed for films deposited in vacuum and under an Ar/H 2 gas mixture (93/7%), respectively. Optical changes were also achieved by ex situ hydrogenation under hydrogen gas pressure of 15 bars at 200°C. However, after ex situ hydrogenation, the optical transmittance of the Mg-based hydrogenated thin films did not exceed 25%. Such limitation was attributed to oxygen contamination, as deduced by High Resolution Transmission Electron Microscopy observations, showing the coexistence of both Mg-based and MgO phases for as-deposited films. A significant decrease in oxygen contamination was successfully achieved with the addition of carbon, leading to the preparation of (Mg-based)-C x (x b 20%) thin films showing a faster and easier hydrogenation.

Solar Energy Materials and Solar Cells, 2006

Aiming at improving the electrochromic properties of NiO thin films, well-known as anodic counter... more Aiming at improving the electrochromic properties of NiO thin films, well-known as anodic counter electrodes, the effect of tungsten addition was investigated. Ni-W-O thin films were deposited by pulsed laser deposition in optimized conditions, namely a 10 À1 mbar oxygen pressure and a room temperature substrate. The presence of W led to a progressive film amorphization. An increase in cyclability for Ni-W-O (5% t WO 3) electrode, cycled in KOH 1 M electrolyte, was associated with a limited dissolution of the oxidized phases with tungsten addition. HRTEM investigations of cycled films revealed that the stabilization is correlated to the existence of an a(II) hydroxide phase.

Physica Scripta, 2005

The quantum physics of light is a most fascinating field. Here I present a very personal viewpoin... more The quantum physics of light is a most fascinating field. Here I present a very personal viewpoint, focusing on my own path to quantum entanglement and then on to applications. I have been fascinated by quantum physics ever since I heard about it for the first time in school. The theory struck me immediately for two reasons: (1) its immense mathematical beauty, and (2) the unparalleled precision to which its predictions have been verified again and again. Particularly fascinating for me were the predictions of quantum mechanics for individual particles, individual quantum systems. Surprisingly, the experimental realization of many of these fundamental phenomena has led to novel ideas for applications. Starting from my early experiments with neutrons, I later became interested in quantum entanglement, initially focusing on multi-particle entanglement like GHZ states. This work opened the experimental possibility to do quantum teleportation and quantum hyper-dense coding. The latter became the first entanglement-based quantum experiment breaking a classical limitation. One of the most fascinating phenomena is entanglement swapping, the teleportation of an entangled state. This phenomenon is fundamentally interesting because it can entangle two pairs of particles which do not share any common past. Surprisingly, it also became an important ingredient in a number of applications, including quantum repeaters which will connect future quantum computers with each other. Another application is entanglement-based quantum cryptography where I present some recent long-distance experiments. Entanglement swapping has also been applied in very recent so-called loophole-free tests of Bell's theorem. Within the physics community such loophole-free experiments are perceived as providing nearly definitive proof that local realism is untenable. While, out of principle, local realism can never be excluded entirely, the 2015 achievements narrow down the remaining possibilities for local realistic explanations of the quantum phenomenon of entanglement in a significant way. These experiments may go down in the history books of science. Future experiments will address particularly the freedom-of-choice loophole using cosmic sources of randomness. Such experiments confirm that unconditionally secure quantum cryptography is possible, since quantum cryptography based on Bell's theorem can provide unconditional security. The fact that the experiments were loophole-free proves that an eavesdropper cannot avoid detection in an experiment that correctly follows the protocol. I finally discuss some recent experiments with single-and entangled-photon states in higher dimensions. Such experiments realized quantum entanglement between two photons, each with quantum numbers beyond 10 000 and also simultaneous entanglement of two photons where each carries more than 100 dimensions. Thus they offer the possibility of quantum communication with more than one bit or qubit per photon. The paper concludes discussing Einstein's contributions and viewpoints of quantum mechanics. Even if some of his positions are not supported by recent experiments, he has to be given credit for the fact that his analysis of fundamental issues gave rise to developments which led to a new information technology. Finally, I reflect on some of the lessons learned by the fact that Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Journal of Alloys and Compounds, 2008

We report, high surface area (up to 200 m 2 /g) nanocrystalline niobium oxide (so called p-Nb 2 O... more We report, high surface area (up to 200 m 2 /g) nanocrystalline niobium oxide (so called p-Nb 2 O 5) synthesized by 'chimie douce' route and its importance in enhancing the hydrogen sorption properties of MgH 2. p-Nb 2 O 5 induces faster kinetics than commonly used commercial Nb 2 O 5 (c-Nb 2 O 5) when ball milled with MgH 2 (named (MgH 2) catalyst) by reducing the time of desorption from 35 min in (MgH 2) c-Nb 2 O 5 to 12 min in (MgH 2) p-Nb 2 O 5 at 300 • C. The BET surface area of as-prepared Nb 2 O 5 was tuned by heat treatment and its effect on sorption properties was studied. Among them, both p-Nb 2 O 5 and Nb 2 O 5 :350 (p-Nb 2 O 5 heated to 350 • C with a BET specific surface area of 46 m 2 /g) desorb 5 wt.% within 12 min, exhibiting the best catalytic activity. Furthermore, thanks to the addition of high surface area Nb 2 O 5 , the desorption temperature was successfully lowered down to 200 • C, with a significant amount of desorbed hydrogen (4.5 wt.%). In contrast, the composite (MgH 2) c-Nb 2 O 5 shows no desorption at this "low" temperature.

Journal of Alloys and Compounds, 2008

Enhanced sorption properties of ball-milled MgH2 are reported by adding NbF5. Among various catal... more Enhanced sorption properties of ball-milled MgH2 are reported by adding NbF5. Among various catalyst amounts, 2mol% of NbF5 reveals to be the optimum concentration leading to significant reduction of the desorption temperature as well as faster kinetics of ball-milled MgH2. At 200°C, temperature at which MgH2 does not show any activity, MgH2NbF5/2 mol% composite desorbs 3.2wt.% of H2 in 50mins. Interestingly,

Ionics, 1997

... Center, RCEL Warren, Michigan 48090, USA 2Laboratoire des Milieux D6sordonn6s et H6t6rogbnes,... more ... Center, RCEL Warren, Michigan 48090, USA 2Laboratoire des Milieux D6sordonn6s et H6t6rogbnes, associ6 au CNRS UA800 Universit6 Pierre et Marie Curie, 4 ... Materials LiMO 2 (M=Ni, Co) with layered structure that belong to the crystallo-graphic R 3m space group have ...

International Journal of Hydrogen Energy, 2014

Electrochemical conversion reaction of MgH 2 with Li ion enables the production of in-situ nanome... more Electrochemical conversion reaction of MgH 2 with Li ion enables the production of in-situ nanometric Mg and MgH 2 particles so-called (nano-Mg) INSITU and [(nano-MgH 2) INSITU ] showing interesting hydrogen sorption properties with hydrogen absorption at 100 C under 10 bars of hydrogen pressure (PH 2) and desorption at 200 C under primary vacuum, respectively. Differential Scanning Calorimetry (DSC) measurements of MgH 2 electrochemically prepared confirmed a decrease in the desorption temperature from 416 C to 295 C and in the heat of formation from À74 kJ mole mol À1 (H 2) À1 to À56 kJ mol À1 (H 2) À1 for commercial (particle size diameter: 10 mme100 mm) and as prepared MgH 2 hydride (particle size: 10 nme40 nm), respectively.

International Journal of Hydrogen Energy, 2007

This paper describes the improvement of hydrogen sorption capacity and kinetics of MgH 2 by addit... more This paper describes the improvement of hydrogen sorption capacity and kinetics of MgH 2 by addition of high surface area (≈ 100 m 2 /g) Raney nickel (RN). Herein, we demonstrate that enhanced hydrogen sorption by MgH 2 due to RN is not only linked to the catalytic nature of Ni, but also correlates well with the BET surface area for the MgH 2-Ni composites. The Raney Ni also tends to form the less stable Mg 2 NiH 4 hydrides, which desorb hydrogen at much higher pressure as compared with that of the MgH 2. We have observed a significant improvement in hydrogen sorption capacity and increase in pressure of hydrogen desorption for MgH 2 catalyzed by RN.

Solar Energy Materials and Solar Cells, 2014

Electrochromic nickel oxide (Ni 1 À x O) pigment powder which was made from nickel acetate reacti... more Electrochromic nickel oxide (Ni 1 À x O) pigment powder which was made from nickel acetate reacting with H 2 O 2 /urea solution followed by heat treatment of xerogels at 400 1C (24 h) was milled with zirconia beads in pure water or water with added nickel oxyhydroxy precipitate acting simultaneously as the dispersant and the coating binder. The corresponding pigment particle suspensions were spin coated on FTO glass and flexible ITO-PET foils, respectively, and cured at 150 1C. The optical properties of the deposited pigment coatings on FTO glass substrates were determined with an UV VIS spectrometer, providing total direct transmittance (TT), total diffuse transmittance (DT) and haze (in %). Haze increased with the coating thickness but did not exceed 4%. SEM micrographs of the deposited pigment coatings revealed that they consisted of agglomerated Ni 1 À x O pigment with voids. Potential cycling of Ni 1 À x O pigment coatings and Ni 1 À x O thin films was performed in 1 M LiClO 4 /PC and 0.1 M TBA þ triflate/PC electrolytes, revealing that the pigment coatings exhibited electrochemical and electrochromic activity also in lithium free (aprotic) electrolyte, while variations of the oxidation and reduction reaction peaks at various scan rates confirmed the presence of surface electrochemical reactions. The near-grazing incidence angle reflection-absorption spectroscopic technique (IR RA) was employed for identifying surface and inner-grain Ni-O stretching modes, the former being responsible for observed electrochemical properties, which was also demonstrated from the ex situ IR RA measurements performed for coatings charged/discharged in 1 M LiClO 4 /PC and 0.1 M TBA þ triflate/PC electrolytes. The results disclosed in this study suggest that the electrochromic effect was not in direct correlation with the de-insertion/insertion of small ions into the NiO (bunsenite) grains but rather the pigment coatings behave similarly to nickel oxide electrochemical capacitors. The electrochromic response of a flexible EC devices made either of PEDOT (self-standing foil) or WO 3 and Ni 1 À x O pigment coatings glued with PMMA based electrolytes without and with lithium salt were recorded for the demonstration of the possible practical application of wet deposited Ni 1 À x O pigment coatings made as "electrochromic" paints.

Applied Surface Science, 2007

Applied Surface Science, 2006

Iron fluoride thin films were successfully grown by Pulsed Laser Deposition (PLD), and their phys... more Iron fluoride thin films were successfully grown by Pulsed Laser Deposition (PLD), and their physico-chemical properties and electrochemical behaviours were examined by adjusting the deposition conditions, such as the target nature (FeF 2 or FeF 3), the substrate temperature (T s 600 8C), the gas pressure (under vacuum or in oxygen atmosphere) and the repetition rates (2 and 10 Hz). Irrespective of the FeF 2 or FeF 3 target nature, iron fluoride thin films, deposited at 600 8C under vacuum, showed X-ray diffraction (XRD) patterns corresponding to the FeF 2 phase. On the other hand, iron fluoride thin films deposited at room temperature (RT) from FeF 2 target were amorphous, whereas the thin films deposited from FeF 3 target consisted of a two-phase mixture of FeF 3 and FeF 2 showing sharp and broad diffraction peaks by XRD, respectively. Their electrochemical behaviour in rechargeable lithium cells was investigated in the 0.05-3.60 V voltage window. Despite a large irreversible capacity on the first discharge, good cycling life was observed up to 30 cycles. Finally, their electrochemical properties were compared to the ones of iron oxide thin films.

Applied Surface Science, 1999

Thin films of tungsten oxide were deposited on SnO :F coated glass using pulsed laser deposition.... more Thin films of tungsten oxide were deposited on SnO :F coated glass using pulsed laser deposition. The structure, 2 morphology, composition of the films and thus the electrochromic properties are strongly dependent on the conditions of deposition. Emphasis is being made on both the influence of the oxygen pressure and the temperature of deposition. Crystallized films are obtained when deposited at 4008C with an oxygen pressure of 10 y1 mbar while an oxygen pressure of 10 y2 mbar leads to amorphous films whatever the substrate temperature is. For the lower oxygen pressure, blue colored and conductive films are deposited whereas colorless insulator films are obtained for an oxygen pressure of 10 y1 mbar at room Ž. temperature RT. The estimated optical band gaps for the films were found to be 3.2 eV when deposited at RT and 2.8 eV when deposited on a 4008C substrate while having an oxygen pressure of 10 y1 mbar. Using Raman spectroscopy, the decrease of the optical band gap was ascribed to a decrease of the W5OrO-W-O ratio correlated to an increase of the cluster size of tungsten oxide with crystallinity. By IR spectroscopy, we were able to relate the better electrochromic properties of the colorless films deposited at RT in an oxygen pressure of 10 y1 mbar, to the presence of water.

Applied Surface Science, 2011

... In order to throw some light on this behavior, further characterizations including Hall measu... more ... In order to throw some light on this behavior, further characterizations including Hall measurements are currently in progress. Acknowledgements: The authors wish to thank Jacques Perri re (INSP) for RBS analysis, Abdelaadim Danine (FST Marrakech) for thin film deposition. ...

Mixed vanadium and niobium tungsten oxide W–M–O (M=V, Nb) thin films were prepared by sol-gel fro... more Mixed vanadium and niobium tungsten oxide W–M–O (M=V, Nb) thin films were prepared by sol-gel from solution of tungsten oxychloride (WOCl4) and vanadium oxypropoxide (VO(OPri)3) or niobium oxybutoxide (Nb(OBun)5), respectively. The annealing temperature and time were optimized to 200°C and 10min. W–M–O (M=V, Nb) thin films were characterized by means of optical (transmittance) and electrochemical (cyclic voltammetry) methods. Evidence of

This paper reports the enhancement of the electrochromic properties in the infrared, IR, region o... more This paper reports the enhancement of the electrochromic properties in the infrared, IR, region of radio frequency sputtered WO3 thin films thanks to a careful optimization of the deposition conditions. From the combination of various techniques of characterization, the optical ...

ACS Applied Materials & Interfaces, 2019

Novel design of electrochromic devices ECDs, known for their ability to modify their optical prop... more Novel design of electrochromic devices ECDs, known for their ability to modify their optical properties under an applied voltage, based on a minimization of the number of layers is reported. The use of a metallic electrode, playing the role of both the conductive layer as well as the counter electrode allows to simplify the assembly of commonly 5 layers battery type device to 4-layers ECD. Further minimization of the number of layers is achieved by using a conductive and electrochromic material. The novelty of the device configuration is illustrated using poly(3,4-ethylenedioxythiophene) PEDOT based materials as EC layer, lithium based ionic liquid as electrolyte and Ag as counter electrode. Such 4-or 3-layer ECD deposited on paper substrate switches from light to deep blue in a narrow 0.7 V voltage window. Preliminary investigations of the mechanism indicate traces of Ag on the PEDOT layer upon cycling. Finally, the printed ECD is successfully activated using a mobile phone.

The Journal of Physical Chemistry B, 2005

The oxygen vacancy in WO(3) has previously been implicated in the electrochromism mechanism in th... more The oxygen vacancy in WO(3) has previously been implicated in the electrochromism mechanism in this material. Previous theoretical calculations on the oxygen vacancy in WO(3) have not considered the full range of crystal structures adopted by the material. Here we report studies of the oxygen vacancy in seven crystal phases. The use of a very accurate tungsten plane-wave pseudopotential means that a byproduct of this study is a more detailed and complete picture of undefected WO(3) than previously available. Electronic structures of the crystal phases in both undefected and defected systems have been calculated and are discussed. The band gap in WO(3) is dependent upon bonding-antibonding interactions, these being dependent upon overlap in each direction. The effect of an oxygen vacancy is dependent upon the availability of both Op and Wd electrons, this being different for the various phases. A variety of behavior is predicted, which may be explained in terms of O2p-W5d mixing, including the formation of long W-W dimer bonds. It is found that the nature of a polaron in this material is dependent upon both the crystal structure and distribution of oxygen vacancies.

Powder Technology, 2002

The influence of grinding on the structure and catalytic performances of two families of oxides, ... more The influence of grinding on the structure and catalytic performances of two families of oxides, namely the perovskite-type La 0.8 Sr 0.2 MnO 3 F k and the spinel-type Li-Mn-O, was investigated. Ball-milling of the well-known La 0.8 Sr 0.2 MnO 3 F k prepared either by a solid state reaction or by a sol-gel method led to (i) a decrease in carbon black combustion temperature of 100 jC (T C = 540 jC) and of 40 jC (T C = 505 jC) for ceramic and sol-gel ground 5-h samples, respectively, and (ii) to faster kinetics and higher rates of toluene conversion. A greater enhancement of the catalytic performances was obtained by using mechanical milled lithiated manganese oxides that are reported as promising catalyst candidates for the first time. Li-Mn-O catalysts were synthesized by room temperature mechanochemistry of a stoichiometric mixture of Li 2 O and MnO 2 using various milling times (0 < t milling < 15 h). The nonstoichiometry, large surface area and disorder nature of the ground samples were of great benefit regarding catalytic applications. A remarkable decrease in the carbon black combustion temperature of 200 jC (from 650 to 450 jC) was obtained when using a mixture of Li 2 O and MnO 2 ground for 3 or 4 h. This low T C value favorably compares with the T C of 500 jC of ceramic LiMn 2 O 4 , which shows, however, better catalytic performances than most of the perovskite-type oxides. The grinding proves to be efficient as well for volatile organic compounds (VOCs) combustion. The inactive ceramic LiMn 2 O 4 exhibits a 100% toluene conversion rate for a temperature lower than 200 jC when ground 5 h.

Thin Solid Films, 2006

Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny met... more Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny metallic to transparent states were observed for films deposited in vacuum and under an Ar/H 2 gas mixture (93/7%), respectively. Optical changes were also achieved by ex situ hydrogenation under hydrogen gas pressure of 15 bars at 200°C. However, after ex situ hydrogenation, the optical transmittance of the Mg-based hydrogenated thin films did not exceed 25%. Such limitation was attributed to oxygen contamination, as deduced by High Resolution Transmission Electron Microscopy observations, showing the coexistence of both Mg-based and MgO phases for as-deposited films. A significant decrease in oxygen contamination was successfully achieved with the addition of carbon, leading to the preparation of (Mg-based)-C x (x b 20%) thin films showing a faster and easier hydrogenation.

Solar Energy Materials and Solar Cells, 2006

Aiming at improving the electrochromic properties of NiO thin films, well-known as anodic counter... more Aiming at improving the electrochromic properties of NiO thin films, well-known as anodic counter electrodes, the effect of tungsten addition was investigated. Ni-W-O thin films were deposited by pulsed laser deposition in optimized conditions, namely a 10 À1 mbar oxygen pressure and a room temperature substrate. The presence of W led to a progressive film amorphization. An increase in cyclability for Ni-W-O (5% t WO 3) electrode, cycled in KOH 1 M electrolyte, was associated with a limited dissolution of the oxidized phases with tungsten addition. HRTEM investigations of cycled films revealed that the stabilization is correlated to the existence of an a(II) hydroxide phase.

Physica Scripta, 2005

The quantum physics of light is a most fascinating field. Here I present a very personal viewpoin... more The quantum physics of light is a most fascinating field. Here I present a very personal viewpoint, focusing on my own path to quantum entanglement and then on to applications. I have been fascinated by quantum physics ever since I heard about it for the first time in school. The theory struck me immediately for two reasons: (1) its immense mathematical beauty, and (2) the unparalleled precision to which its predictions have been verified again and again. Particularly fascinating for me were the predictions of quantum mechanics for individual particles, individual quantum systems. Surprisingly, the experimental realization of many of these fundamental phenomena has led to novel ideas for applications. Starting from my early experiments with neutrons, I later became interested in quantum entanglement, initially focusing on multi-particle entanglement like GHZ states. This work opened the experimental possibility to do quantum teleportation and quantum hyper-dense coding. The latter became the first entanglement-based quantum experiment breaking a classical limitation. One of the most fascinating phenomena is entanglement swapping, the teleportation of an entangled state. This phenomenon is fundamentally interesting because it can entangle two pairs of particles which do not share any common past. Surprisingly, it also became an important ingredient in a number of applications, including quantum repeaters which will connect future quantum computers with each other. Another application is entanglement-based quantum cryptography where I present some recent long-distance experiments. Entanglement swapping has also been applied in very recent so-called loophole-free tests of Bell's theorem. Within the physics community such loophole-free experiments are perceived as providing nearly definitive proof that local realism is untenable. While, out of principle, local realism can never be excluded entirely, the 2015 achievements narrow down the remaining possibilities for local realistic explanations of the quantum phenomenon of entanglement in a significant way. These experiments may go down in the history books of science. Future experiments will address particularly the freedom-of-choice loophole using cosmic sources of randomness. Such experiments confirm that unconditionally secure quantum cryptography is possible, since quantum cryptography based on Bell's theorem can provide unconditional security. The fact that the experiments were loophole-free proves that an eavesdropper cannot avoid detection in an experiment that correctly follows the protocol. I finally discuss some recent experiments with single-and entangled-photon states in higher dimensions. Such experiments realized quantum entanglement between two photons, each with quantum numbers beyond 10 000 and also simultaneous entanglement of two photons where each carries more than 100 dimensions. Thus they offer the possibility of quantum communication with more than one bit or qubit per photon. The paper concludes discussing Einstein's contributions and viewpoints of quantum mechanics. Even if some of his positions are not supported by recent experiments, he has to be given credit for the fact that his analysis of fundamental issues gave rise to developments which led to a new information technology. Finally, I reflect on some of the lessons learned by the fact that Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Journal of Alloys and Compounds, 2008

We report, high surface area (up to 200 m 2 /g) nanocrystalline niobium oxide (so called p-Nb 2 O... more We report, high surface area (up to 200 m 2 /g) nanocrystalline niobium oxide (so called p-Nb 2 O 5) synthesized by 'chimie douce' route and its importance in enhancing the hydrogen sorption properties of MgH 2. p-Nb 2 O 5 induces faster kinetics than commonly used commercial Nb 2 O 5 (c-Nb 2 O 5) when ball milled with MgH 2 (named (MgH 2) catalyst) by reducing the time of desorption from 35 min in (MgH 2) c-Nb 2 O 5 to 12 min in (MgH 2) p-Nb 2 O 5 at 300 • C. The BET surface area of as-prepared Nb 2 O 5 was tuned by heat treatment and its effect on sorption properties was studied. Among them, both p-Nb 2 O 5 and Nb 2 O 5 :350 (p-Nb 2 O 5 heated to 350 • C with a BET specific surface area of 46 m 2 /g) desorb 5 wt.% within 12 min, exhibiting the best catalytic activity. Furthermore, thanks to the addition of high surface area Nb 2 O 5 , the desorption temperature was successfully lowered down to 200 • C, with a significant amount of desorbed hydrogen (4.5 wt.%). In contrast, the composite (MgH 2) c-Nb 2 O 5 shows no desorption at this "low" temperature.

Journal of Alloys and Compounds, 2008

Enhanced sorption properties of ball-milled MgH2 are reported by adding NbF5. Among various catal... more Enhanced sorption properties of ball-milled MgH2 are reported by adding NbF5. Among various catalyst amounts, 2mol% of NbF5 reveals to be the optimum concentration leading to significant reduction of the desorption temperature as well as faster kinetics of ball-milled MgH2. At 200°C, temperature at which MgH2 does not show any activity, MgH2NbF5/2 mol% composite desorbs 3.2wt.% of H2 in 50mins. Interestingly,

Ionics, 1997

... Center, RCEL Warren, Michigan 48090, USA 2Laboratoire des Milieux D6sordonn6s et H6t6rogbnes,... more ... Center, RCEL Warren, Michigan 48090, USA 2Laboratoire des Milieux D6sordonn6s et H6t6rogbnes, associ6 au CNRS UA800 Universit6 Pierre et Marie Curie, 4 ... Materials LiMO 2 (M=Ni, Co) with layered structure that belong to the crystallo-graphic R 3m space group have ...

International Journal of Hydrogen Energy, 2014

Electrochemical conversion reaction of MgH 2 with Li ion enables the production of in-situ nanome... more Electrochemical conversion reaction of MgH 2 with Li ion enables the production of in-situ nanometric Mg and MgH 2 particles so-called (nano-Mg) INSITU and [(nano-MgH 2) INSITU ] showing interesting hydrogen sorption properties with hydrogen absorption at 100 C under 10 bars of hydrogen pressure (PH 2) and desorption at 200 C under primary vacuum, respectively. Differential Scanning Calorimetry (DSC) measurements of MgH 2 electrochemically prepared confirmed a decrease in the desorption temperature from 416 C to 295 C and in the heat of formation from À74 kJ mole mol À1 (H 2) À1 to À56 kJ mol À1 (H 2) À1 for commercial (particle size diameter: 10 mme100 mm) and as prepared MgH 2 hydride (particle size: 10 nme40 nm), respectively.

International Journal of Hydrogen Energy, 2007

This paper describes the improvement of hydrogen sorption capacity and kinetics of MgH 2 by addit... more This paper describes the improvement of hydrogen sorption capacity and kinetics of MgH 2 by addition of high surface area (≈ 100 m 2 /g) Raney nickel (RN). Herein, we demonstrate that enhanced hydrogen sorption by MgH 2 due to RN is not only linked to the catalytic nature of Ni, but also correlates well with the BET surface area for the MgH 2-Ni composites. The Raney Ni also tends to form the less stable Mg 2 NiH 4 hydrides, which desorb hydrogen at much higher pressure as compared with that of the MgH 2. We have observed a significant improvement in hydrogen sorption capacity and increase in pressure of hydrogen desorption for MgH 2 catalyzed by RN.

Solar Energy Materials and Solar Cells, 2014

Electrochromic nickel oxide (Ni 1 À x O) pigment powder which was made from nickel acetate reacti... more Electrochromic nickel oxide (Ni 1 À x O) pigment powder which was made from nickel acetate reacting with H 2 O 2 /urea solution followed by heat treatment of xerogels at 400 1C (24 h) was milled with zirconia beads in pure water or water with added nickel oxyhydroxy precipitate acting simultaneously as the dispersant and the coating binder. The corresponding pigment particle suspensions were spin coated on FTO glass and flexible ITO-PET foils, respectively, and cured at 150 1C. The optical properties of the deposited pigment coatings on FTO glass substrates were determined with an UV VIS spectrometer, providing total direct transmittance (TT), total diffuse transmittance (DT) and haze (in %). Haze increased with the coating thickness but did not exceed 4%. SEM micrographs of the deposited pigment coatings revealed that they consisted of agglomerated Ni 1 À x O pigment with voids. Potential cycling of Ni 1 À x O pigment coatings and Ni 1 À x O thin films was performed in 1 M LiClO 4 /PC and 0.1 M TBA þ triflate/PC electrolytes, revealing that the pigment coatings exhibited electrochemical and electrochromic activity also in lithium free (aprotic) electrolyte, while variations of the oxidation and reduction reaction peaks at various scan rates confirmed the presence of surface electrochemical reactions. The near-grazing incidence angle reflection-absorption spectroscopic technique (IR RA) was employed for identifying surface and inner-grain Ni-O stretching modes, the former being responsible for observed electrochemical properties, which was also demonstrated from the ex situ IR RA measurements performed for coatings charged/discharged in 1 M LiClO 4 /PC and 0.1 M TBA þ triflate/PC electrolytes. The results disclosed in this study suggest that the electrochromic effect was not in direct correlation with the de-insertion/insertion of small ions into the NiO (bunsenite) grains but rather the pigment coatings behave similarly to nickel oxide electrochemical capacitors. The electrochromic response of a flexible EC devices made either of PEDOT (self-standing foil) or WO 3 and Ni 1 À x O pigment coatings glued with PMMA based electrolytes without and with lithium salt were recorded for the demonstration of the possible practical application of wet deposited Ni 1 À x O pigment coatings made as "electrochromic" paints.

Applied Surface Science, 2007

Applied Surface Science, 2006

Iron fluoride thin films were successfully grown by Pulsed Laser Deposition (PLD), and their phys... more Iron fluoride thin films were successfully grown by Pulsed Laser Deposition (PLD), and their physico-chemical properties and electrochemical behaviours were examined by adjusting the deposition conditions, such as the target nature (FeF 2 or FeF 3), the substrate temperature (T s 600 8C), the gas pressure (under vacuum or in oxygen atmosphere) and the repetition rates (2 and 10 Hz). Irrespective of the FeF 2 or FeF 3 target nature, iron fluoride thin films, deposited at 600 8C under vacuum, showed X-ray diffraction (XRD) patterns corresponding to the FeF 2 phase. On the other hand, iron fluoride thin films deposited at room temperature (RT) from FeF 2 target were amorphous, whereas the thin films deposited from FeF 3 target consisted of a two-phase mixture of FeF 3 and FeF 2 showing sharp and broad diffraction peaks by XRD, respectively. Their electrochemical behaviour in rechargeable lithium cells was investigated in the 0.05-3.60 V voltage window. Despite a large irreversible capacity on the first discharge, good cycling life was observed up to 30 cycles. Finally, their electrochemical properties were compared to the ones of iron oxide thin films.

Applied Surface Science, 1999

Thin films of tungsten oxide were deposited on SnO :F coated glass using pulsed laser deposition.... more Thin films of tungsten oxide were deposited on SnO :F coated glass using pulsed laser deposition. The structure, 2 morphology, composition of the films and thus the electrochromic properties are strongly dependent on the conditions of deposition. Emphasis is being made on both the influence of the oxygen pressure and the temperature of deposition. Crystallized films are obtained when deposited at 4008C with an oxygen pressure of 10 y1 mbar while an oxygen pressure of 10 y2 mbar leads to amorphous films whatever the substrate temperature is. For the lower oxygen pressure, blue colored and conductive films are deposited whereas colorless insulator films are obtained for an oxygen pressure of 10 y1 mbar at room Ž. temperature RT. The estimated optical band gaps for the films were found to be 3.2 eV when deposited at RT and 2.8 eV when deposited on a 4008C substrate while having an oxygen pressure of 10 y1 mbar. Using Raman spectroscopy, the decrease of the optical band gap was ascribed to a decrease of the W5OrO-W-O ratio correlated to an increase of the cluster size of tungsten oxide with crystallinity. By IR spectroscopy, we were able to relate the better electrochromic properties of the colorless films deposited at RT in an oxygen pressure of 10 y1 mbar, to the presence of water.

Applied Surface Science, 2011

... In order to throw some light on this behavior, further characterizations including Hall measu... more ... In order to throw some light on this behavior, further characterizations including Hall measurements are currently in progress. Acknowledgements: The authors wish to thank Jacques Perri re (INSP) for RBS analysis, Abdelaadim Danine (FST Marrakech) for thin film deposition. ...

Mixed vanadium and niobium tungsten oxide W–M–O (M=V, Nb) thin films were prepared by sol-gel fro... more Mixed vanadium and niobium tungsten oxide W–M–O (M=V, Nb) thin films were prepared by sol-gel from solution of tungsten oxychloride (WOCl4) and vanadium oxypropoxide (VO(OPri)3) or niobium oxybutoxide (Nb(OBun)5), respectively. The annealing temperature and time were optimized to 200°C and 10min. W–M–O (M=V, Nb) thin films were characterized by means of optical (transmittance) and electrochemical (cyclic voltammetry) methods. Evidence of

This paper reports the enhancement of the electrochromic properties in the infrared, IR, region o... more This paper reports the enhancement of the electrochromic properties in the infrared, IR, region of radio frequency sputtered WO3 thin films thanks to a careful optimization of the deposition conditions. From the combination of various techniques of characterization, the optical ...