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Dissertation
Dopage d'un oxyde métallique semi-conducteur à partir d'une phase solide
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Year: 2022 Publisher: Liège Université de Liège (ULiège)

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Les oxydes transparents sont des matériaux présentant des propriétés opto-électroniques intéressantes pour de nombreuses applications technologiques. La majorité de ces semi-conducteurs présentent des propriétés électriques associées à un dopage de type-n. Or, le développement de matériaux de type-p présentant des propriétés physiques aussi intéressantes que leurs homologues de type-n est, encore aujourd'hui, un défi pour la communauté scientifique. Dans ce travail, nous avons développé une méthode originale de fabrication de films minces de ZnO dopé. Pour ce faire, nous avons incorporé des nanofils d’argent (AgNWs) entre deux films minces de ZnO déposés par pulvérisation cathodique. Les propriétés physiques de ces composites ont été étudiées suivant la quantité de nanofils ainsi qu’en fonction de la température de recuit de l’échantillon post-synthèse. Le but de cette étude est de mettre en évidence l’impact de l’ajout et de la diffusion des nanofils d’argent dans le ZnO sur les propriétés électriques et optiques de ce composite tout en optimisant la méthode de synthèse des échantillons. Sur base de cette méthodologie, nous avons mis en évidence trois gammes de température de recuit. Jusqu'à 300°C, nous observons une diminution de la résistance électrique suivie d'une augmentation notable à 350°C, toute deux identifiées à l’évolution des propriétés physiques du ZnO. Ensuite, pour des températures de plus de 450°C, nous observons une diminution de la résistivité grâce aux nanofils d'argent. Une valeur optimale pour la densité de nanofils a été déterminée aux alentours de 6.4 µg/cm² pour une température de recuit de 40°C associée à une résistivité de 4.31 Ωcm et une transmittance optique de 73.3% dans le domaine du visible.


Book
Synthesis and Characterization of Ferroelectrics
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Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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The Special Issue on “Synthesis and Characterization of Ferroelectrics” reports on several physical properties of ferroelectric materials and their technological aspects. Different substitution mechanisms provide ideas toward future improvement of lead-free (Ba,Ca)(Zr,Ti)O3 piezoelectric ceramics, including the electrocaloric effect, fluorescence, and energy storage. It is established that axial and radial element segregation differently influences electrical properties of 0.68Pb(Mg1/3Nb2/3)0.32PbTiO3 (PMN-32PT for short) single crystals. While the electrical properties along the axial direction strongly depend on the PbTiO3 content, the electrical properties along the axial direction are mainly determined by the ratio of Nb and Mg. On the other hand, Fe-substitution of PMN-32PT crystals lead to an enhancement of the coercive field due to wall pinning induced by charged defect dipoles. It is also found, that capacitors based on Pt/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 thin films display good fatigue resistance and retention. Another lead-free thin film capacitor fabricated from Ba0.3Sr0.7Zr0.18Ti0.82 features a low leakage current density and high breakdown strength. Such capacitors are essential for energy storage. Furthermore, an enhanced electrocaloric effect on 0.73Pb(Mg1/3Nb2/3)0.27PbTiO3 single crystals is demonstrated. This effect is promising for novel solid-state cooling systems.


Book
Synthesis and Characterization of Ferroelectrics
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Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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The Special Issue on “Synthesis and Characterization of Ferroelectrics” reports on several physical properties of ferroelectric materials and their technological aspects. Different substitution mechanisms provide ideas toward future improvement of lead-free (Ba,Ca)(Zr,Ti)O3 piezoelectric ceramics, including the electrocaloric effect, fluorescence, and energy storage. It is established that axial and radial element segregation differently influences electrical properties of 0.68Pb(Mg1/3Nb2/3)0.32PbTiO3 (PMN-32PT for short) single crystals. While the electrical properties along the axial direction strongly depend on the PbTiO3 content, the electrical properties along the axial direction are mainly determined by the ratio of Nb and Mg. On the other hand, Fe-substitution of PMN-32PT crystals lead to an enhancement of the coercive field due to wall pinning induced by charged defect dipoles. It is also found, that capacitors based on Pt/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 thin films display good fatigue resistance and retention. Another lead-free thin film capacitor fabricated from Ba0.3Sr0.7Zr0.18Ti0.82 features a low leakage current density and high breakdown strength. Such capacitors are essential for energy storage. Furthermore, an enhanced electrocaloric effect on 0.73Pb(Mg1/3Nb2/3)0.27PbTiO3 single crystals is demonstrated. This effect is promising for novel solid-state cooling systems.


Book
Synthesis and Characterization of Ferroelectrics
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Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

The Special Issue on “Synthesis and Characterization of Ferroelectrics” reports on several physical properties of ferroelectric materials and their technological aspects. Different substitution mechanisms provide ideas toward future improvement of lead-free (Ba,Ca)(Zr,Ti)O3 piezoelectric ceramics, including the electrocaloric effect, fluorescence, and energy storage. It is established that axial and radial element segregation differently influences electrical properties of 0.68Pb(Mg1/3Nb2/3)0.32PbTiO3 (PMN-32PT for short) single crystals. While the electrical properties along the axial direction strongly depend on the PbTiO3 content, the electrical properties along the axial direction are mainly determined by the ratio of Nb and Mg. On the other hand, Fe-substitution of PMN-32PT crystals lead to an enhancement of the coercive field due to wall pinning induced by charged defect dipoles. It is also found, that capacitors based on Pt/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 thin films display good fatigue resistance and retention. Another lead-free thin film capacitor fabricated from Ba0.3Sr0.7Zr0.18Ti0.82 features a low leakage current density and high breakdown strength. Such capacitors are essential for energy storage. Furthermore, an enhanced electrocaloric effect on 0.73Pb(Mg1/3Nb2/3)0.27PbTiO3 single crystals is demonstrated. This effect is promising for novel solid-state cooling systems.


Book
Physical Vapor Deposited Biomedical Coatings
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Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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The book outlines a series of developments made in the manufacturing of bio-functional layers via Physical Vapour-Deposited (PVD) technologies for application in various areas of healthcare. The scrutinized PVD methods include Radio-Frequency Magnetron Sputtering (RF-MS), Cathodic Arc Evaporation, Pulsed Electron Deposition and its variants, Pulsed Laser Deposition, and Matrix-Assisted Pulsed Laser Evaporation (MAPLE) due to their great promise, especially in dentistry and orthopaedics. These methods have yet to gain traction for industrialization and large-scale application in biomedicine. A new generation of implant coatings can be made available by the (1) incorporation of organic moieties (e.g., proteins, peptides, enzymes) into thin films using innovative methods such as combinatorial MAPLE, (2) direct coupling of therapeutic agents with bioactive glasses or ceramics within substituted or composite layers via RF-MS, or (3) innovation in high-energy deposition methods, such as arc evaporation or pulsed electron beam methods.


Book
Ion-Substituted Calcium Phosphates Coatings
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Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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Coatings based on hydroxyapatite and calcium phosphates have a significant relevance in several research fields, such as biomaterials, cultural heritage, and water treatment, due to their characteristic properties. Hydroxyapatite can easily accommodate foreign ions, which can either be incorporated into the lattice, thanks to its specific lattice characteristics, or be adsorbed onto its surface. All these substitutions significantly alter the morphology, lattice parameters, and crystallinity of hydroxyapatite so they influence its main properties. These ion substitutions can be sought or can derive from substrate contaminations, which is an important aspect to be evaluated. Finally, this capability can be used to obtain hydroxyapatites with specific properties, such as antibacterial characteristics, among others. For these reasons, the aim of this Special Issue is to document current advances in the field of ion-substituted hydroxyapatites and highlight possible future perspectives regarding their use. Contributions in the form of original articles and review articles are presented, covering different areas of application.


Book
Physical Vapor Deposited Biomedical Coatings
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Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

The book outlines a series of developments made in the manufacturing of bio-functional layers via Physical Vapour-Deposited (PVD) technologies for application in various areas of healthcare. The scrutinized PVD methods include Radio-Frequency Magnetron Sputtering (RF-MS), Cathodic Arc Evaporation, Pulsed Electron Deposition and its variants, Pulsed Laser Deposition, and Matrix-Assisted Pulsed Laser Evaporation (MAPLE) due to their great promise, especially in dentistry and orthopaedics. These methods have yet to gain traction for industrialization and large-scale application in biomedicine. A new generation of implant coatings can be made available by the (1) incorporation of organic moieties (e.g., proteins, peptides, enzymes) into thin films using innovative methods such as combinatorial MAPLE, (2) direct coupling of therapeutic agents with bioactive glasses or ceramics within substituted or composite layers via RF-MS, or (3) innovation in high-energy deposition methods, such as arc evaporation or pulsed electron beam methods.


Book
Ion-Substituted Calcium Phosphates Coatings
Authors: ---
Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

Coatings based on hydroxyapatite and calcium phosphates have a significant relevance in several research fields, such as biomaterials, cultural heritage, and water treatment, due to their characteristic properties. Hydroxyapatite can easily accommodate foreign ions, which can either be incorporated into the lattice, thanks to its specific lattice characteristics, or be adsorbed onto its surface. All these substitutions significantly alter the morphology, lattice parameters, and crystallinity of hydroxyapatite so they influence its main properties. These ion substitutions can be sought or can derive from substrate contaminations, which is an important aspect to be evaluated. Finally, this capability can be used to obtain hydroxyapatites with specific properties, such as antibacterial characteristics, among others. For these reasons, the aim of this Special Issue is to document current advances in the field of ion-substituted hydroxyapatites and highlight possible future perspectives regarding their use. Contributions in the form of original articles and review articles are presented, covering different areas of application.


Book
Ion-Substituted Calcium Phosphates Coatings
Authors: ---
Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

Coatings based on hydroxyapatite and calcium phosphates have a significant relevance in several research fields, such as biomaterials, cultural heritage, and water treatment, due to their characteristic properties. Hydroxyapatite can easily accommodate foreign ions, which can either be incorporated into the lattice, thanks to its specific lattice characteristics, or be adsorbed onto its surface. All these substitutions significantly alter the morphology, lattice parameters, and crystallinity of hydroxyapatite so they influence its main properties. These ion substitutions can be sought or can derive from substrate contaminations, which is an important aspect to be evaluated. Finally, this capability can be used to obtain hydroxyapatites with specific properties, such as antibacterial characteristics, among others. For these reasons, the aim of this Special Issue is to document current advances in the field of ion-substituted hydroxyapatites and highlight possible future perspectives regarding their use. Contributions in the form of original articles and review articles are presented, covering different areas of application.

Keywords

History of engineering & technology --- calcium phosphates --- ion-substituted apatites --- bone regeneration --- plasma-assisted deposition --- solubility --- crystallinity --- composition --- lithium-doped hydroxyapatite coatings --- renewable resources for implant coatings --- pulsed laser deposition --- biocompatibility --- inhibition of microbial biofilms development --- zinc --- hydroxyapatite --- ultrasound measurement --- sol–gel spin coating --- layers --- C. albicans --- S. aureus --- calcium phosphate --- magnesium phosphate --- struvite --- dolomite --- consolidating treatment --- cultural heritage --- ammonium phosphate --- marble --- calcite --- dissolution --- electrodeposition --- protective coatings --- acid attack --- potential --- current --- RF magnetron sputtering --- GLAD --- carbonated hydroxyapatite --- nanomaterials --- coatings --- cave painting --- inorganic consolidant --- ethyl silicate --- TEOS --- non-thermal plasma --- wettability --- bone --- allograft --- autograft --- xenograft --- ion-substituted calcium phosphates --- nanostructured coatings --- calcium phosphates --- ion-substituted apatites --- bone regeneration --- plasma-assisted deposition --- solubility --- crystallinity --- composition --- lithium-doped hydroxyapatite coatings --- renewable resources for implant coatings --- pulsed laser deposition --- biocompatibility --- inhibition of microbial biofilms development --- zinc --- hydroxyapatite --- ultrasound measurement --- sol–gel spin coating --- layers --- C. albicans --- S. aureus --- calcium phosphate --- magnesium phosphate --- struvite --- dolomite --- consolidating treatment --- cultural heritage --- ammonium phosphate --- marble --- calcite --- dissolution --- electrodeposition --- protective coatings --- acid attack --- potential --- current --- RF magnetron sputtering --- GLAD --- carbonated hydroxyapatite --- nanomaterials --- coatings --- cave painting --- inorganic consolidant --- ethyl silicate --- TEOS --- non-thermal plasma --- wettability --- bone --- allograft --- autograft --- xenograft --- ion-substituted calcium phosphates --- nanostructured coatings


Book
Physical Vapor Deposited Biomedical Coatings
Authors: ---
Year: 2021 Publisher: Basel, Switzerland MDPI - Multidisciplinary Digital Publishing Institute

Loading...
Export citation

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Abstract

The book outlines a series of developments made in the manufacturing of bio-functional layers via Physical Vapour-Deposited (PVD) technologies for application in various areas of healthcare. The scrutinized PVD methods include Radio-Frequency Magnetron Sputtering (RF-MS), Cathodic Arc Evaporation, Pulsed Electron Deposition and its variants, Pulsed Laser Deposition, and Matrix-Assisted Pulsed Laser Evaporation (MAPLE) due to their great promise, especially in dentistry and orthopaedics. These methods have yet to gain traction for industrialization and large-scale application in biomedicine. A new generation of implant coatings can be made available by the (1) incorporation of organic moieties (e.g., proteins, peptides, enzymes) into thin films using innovative methods such as combinatorial MAPLE, (2) direct coupling of therapeutic agents with bioactive glasses or ceramics within substituted or composite layers via RF-MS, or (3) innovation in high-energy deposition methods, such as arc evaporation or pulsed electron beam methods.

Keywords

Technology: general issues --- pulsed electron deposition --- thin films --- orthopedic applications --- bioactivity --- ceramic coatings --- yttria-stabilized zirconia --- calcium phosphates --- hydroxyapatite --- biomimetic coatings --- antibacterial coatings --- thin film --- RF magnetron sputtering --- pulsed DC --- Silicon --- bio-coatings --- biomimetics --- laser deposition --- PLD --- MAPLE --- tissue engineering --- cancer --- titanium-based carbonitrides --- coating --- corrosion resistance --- X-ray diffraction --- nanoindentation --- cathodic arc deposition --- biological-derived hydroxyapatite coatings --- lithium doping --- food industrial by-products --- in vivo extraction force --- pulsed laser deposition --- 3D printing --- calcium phosphate --- PEEK --- surface modification --- sputtering --- ToFSIMS --- XPS --- implant coating --- bioactive glass --- copper doping --- gallium doping --- mechanical --- cytocompatibility --- antibacterial --- physical vapour deposition --- thin-films --- medical devices --- biomimicry --- pulsed electron deposition --- thin films --- orthopedic applications --- bioactivity --- ceramic coatings --- yttria-stabilized zirconia --- calcium phosphates --- hydroxyapatite --- biomimetic coatings --- antibacterial coatings --- thin film --- RF magnetron sputtering --- pulsed DC --- Silicon --- bio-coatings --- biomimetics --- laser deposition --- PLD --- MAPLE --- tissue engineering --- cancer --- titanium-based carbonitrides --- coating --- corrosion resistance --- X-ray diffraction --- nanoindentation --- cathodic arc deposition --- biological-derived hydroxyapatite coatings --- lithium doping --- food industrial by-products --- in vivo extraction force --- pulsed laser deposition --- 3D printing --- calcium phosphate --- PEEK --- surface modification --- sputtering --- ToFSIMS --- XPS --- implant coating --- bioactive glass --- copper doping --- gallium doping --- mechanical --- cytocompatibility --- antibacterial --- physical vapour deposition --- thin-films --- medical devices --- biomimicry

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