The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Vincent Consonni - One of the best experts on this subject based on the ideXlab platform.
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effects of the ph on the formation and doping mechanisms of zno nanowires using Aluminum Nitrate and ammonia
Inorganic Chemistry, 2017Co-Authors: Claire Verrier, Estelle Appert, O Chaixpluchery, Laetitia Rapenne, Q Rafhay, Anne Kaminskicachopo, Vincent ConsonniAbstract:The elucidation of the fundamental processes in aqueous solution during the chemical bath deposition of ZnO nanowires (NWs) using zinc Nitrate and hexamethylenetetramine is of great significance: however, their extrinsic doping by foreign elements for monitoring their optical and electrical properties is still challenging. By combining thermodynamic simulations yielding theoretical solubility plots and speciation diagrams with in situ pH measurements and structural, chemical, and optical analyses, we report an in-depth understanding of the pH effects on the formation and Aluminum doping mechanisms of ZnO NWs. By the addition of Aluminum Nitrate with a given relative concentration for the doping and of ammonia over a broad range of concentrations, the pH is shown to strongly influence the shape, diameter, length, and doping magnitude of ZnO NWs. Tuning the dimensions of ZnO NWs by inhibition of their radial growth only proceeds over a specific pH range, where negatively charged Al(OH)4– complexes are predo...
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tunable morphology and doping of zno nanowires by chemical bath deposition using Aluminum Nitrate
Journal of Physical Chemistry C, 2017Co-Authors: Claire Verrier, Estelle Appert, O Chaixpluchery, Laetitia Rapenne, Q Rafhay, Anne Kaminskicachopo, Vincent ConsonniAbstract:Mastering the properties of ZnO nanowires grown by the low temperature chemical bath deposition (CBD) is of crucial importance but is still challenging. We show that the shape, dimensions, and doping of ZnO nanowires can simultaneously be tuned by the addition of Aluminum Nitrate in the standard chemical system using zinc Nitrate, hexamethylenetetramine, and ammonia in aqueous solution. The formation and doping mechanisms of ZnO nanowires are thoroughly investigated by combining chemical, structural, and optical analyses with in situ pH measurements correlated with thermodynamic simulations. We reveal that the electrostatic interactions of Al(OH)4– complexes with the positive m-plane sidewalls of ZnO nanowires at a given pH favor their adsorption as capping agents, reducing the radial growth and promoting the elongation, while favoring the Aluminum uniform incorporation. Importantly, the Aluminum doping is found to be thermally activated above the low temperature of 200 °C under oxygen atmosphere, as indi...
Esmaeil Salahi - One of the best experts on this subject based on the ideXlab platform.
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preparation of mullite from alumina Aluminum Nitrate and kaolin clay through spark plasma sintering process
Ceramics International, 2018Co-Authors: Ebrahim Karimi Saeidabadi, Touradj Ebadzadeh, Esmaeil SalahiAbstract:Abstract In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and Aluminum Nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.
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Preparation of mullite from alumina/Aluminum Nitrate and kaolin clay through spark plasma sintering process
Ceramics International, 2018Co-Authors: Ebrahim Karimi Saeidabadi, Touradj Ebadzadeh, Esmaeil SalahiAbstract:Abstract In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and Aluminum Nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.
Claire Verrier - One of the best experts on this subject based on the ideXlab platform.
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effects of the ph on the formation and doping mechanisms of zno nanowires using Aluminum Nitrate and ammonia
Inorganic Chemistry, 2017Co-Authors: Claire Verrier, Estelle Appert, O Chaixpluchery, Laetitia Rapenne, Q Rafhay, Anne Kaminskicachopo, Vincent ConsonniAbstract:The elucidation of the fundamental processes in aqueous solution during the chemical bath deposition of ZnO nanowires (NWs) using zinc Nitrate and hexamethylenetetramine is of great significance: however, their extrinsic doping by foreign elements for monitoring their optical and electrical properties is still challenging. By combining thermodynamic simulations yielding theoretical solubility plots and speciation diagrams with in situ pH measurements and structural, chemical, and optical analyses, we report an in-depth understanding of the pH effects on the formation and Aluminum doping mechanisms of ZnO NWs. By the addition of Aluminum Nitrate with a given relative concentration for the doping and of ammonia over a broad range of concentrations, the pH is shown to strongly influence the shape, diameter, length, and doping magnitude of ZnO NWs. Tuning the dimensions of ZnO NWs by inhibition of their radial growth only proceeds over a specific pH range, where negatively charged Al(OH)4– complexes are predo...
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tunable morphology and doping of zno nanowires by chemical bath deposition using Aluminum Nitrate
Journal of Physical Chemistry C, 2017Co-Authors: Claire Verrier, Estelle Appert, O Chaixpluchery, Laetitia Rapenne, Q Rafhay, Anne Kaminskicachopo, Vincent ConsonniAbstract:Mastering the properties of ZnO nanowires grown by the low temperature chemical bath deposition (CBD) is of crucial importance but is still challenging. We show that the shape, dimensions, and doping of ZnO nanowires can simultaneously be tuned by the addition of Aluminum Nitrate in the standard chemical system using zinc Nitrate, hexamethylenetetramine, and ammonia in aqueous solution. The formation and doping mechanisms of ZnO nanowires are thoroughly investigated by combining chemical, structural, and optical analyses with in situ pH measurements correlated with thermodynamic simulations. We reveal that the electrostatic interactions of Al(OH)4– complexes with the positive m-plane sidewalls of ZnO nanowires at a given pH favor their adsorption as capping agents, reducing the radial growth and promoting the elongation, while favoring the Aluminum uniform incorporation. Importantly, the Aluminum doping is found to be thermally activated above the low temperature of 200 °C under oxygen atmosphere, as indi...
Touradj Ebadzadeh - One of the best experts on this subject based on the ideXlab platform.
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preparation of mullite from alumina Aluminum Nitrate and kaolin clay through spark plasma sintering process
Ceramics International, 2018Co-Authors: Ebrahim Karimi Saeidabadi, Touradj Ebadzadeh, Esmaeil SalahiAbstract:Abstract In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and Aluminum Nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.
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Preparation of mullite from alumina/Aluminum Nitrate and kaolin clay through spark plasma sintering process
Ceramics International, 2018Co-Authors: Ebrahim Karimi Saeidabadi, Touradj Ebadzadeh, Esmaeil SalahiAbstract:Abstract In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and Aluminum Nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.
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synthesis of ι al2o3 from a mixture of Aluminum Nitrate and carboxymethyl cellulose
Journal of the American Ceramic Society, 2008Co-Authors: Touradj Ebadzadeh, Leyla SharifiAbstract:A simple preparation method for the synthesis of ι-Al2O3 with a mixture of Aluminum Nitrate and carboxymethyl cellulose is proposed. Structural characterization of the microwave-heated samples was performed by X-ray diffraction and the results showed the development of ι-Al2O3 phase at a temperature of 498°C. No α-Al2O3 peaks were observed until the highest temperature reached 1189°C; at this temperature ι-Al2O3 peaks were still strong. In order to elucidate the morphology of the powders, scanning electron microscopy was used and showed the elongated plate-like morphology of synthesized ι-Al2O3.
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Synthesis of ι‐Al2O3 from a Mixture of Aluminum Nitrate and Carboxymethyl Cellulose
Journal of the American Ceramic Society, 2008Co-Authors: Touradj Ebadzadeh, Leyla SharifiAbstract:A simple preparation method for the synthesis of ι-Al2O3 with a mixture of Aluminum Nitrate and carboxymethyl cellulose is proposed. Structural characterization of the microwave-heated samples was performed by X-ray diffraction and the results showed the development of ι-Al2O3 phase at a temperature of 498°C. No α-Al2O3 peaks were observed until the highest temperature reached 1189°C; at this temperature ι-Al2O3 peaks were still strong. In order to elucidate the morphology of the powders, scanning electron microscopy was used and showed the elongated plate-like morphology of synthesized ι-Al2O3.
Ebrahim Karimi Saeidabadi - One of the best experts on this subject based on the ideXlab platform.
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preparation of mullite from alumina Aluminum Nitrate and kaolin clay through spark plasma sintering process
Ceramics International, 2018Co-Authors: Ebrahim Karimi Saeidabadi, Touradj Ebadzadeh, Esmaeil SalahiAbstract:Abstract In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and Aluminum Nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.
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Preparation of mullite from alumina/Aluminum Nitrate and kaolin clay through spark plasma sintering process
Ceramics International, 2018Co-Authors: Ebrahim Karimi Saeidabadi, Touradj Ebadzadeh, Esmaeil SalahiAbstract:Abstract In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and Aluminum Nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.
