The Experts below are selected from a list of 164316 Experts worldwide ranked by ideXlab platform
Yuji Hiruma - One of the best experts on this subject based on the ideXlab platform.
-
detection of morphotropic phase boundary of bi1 2na1 2 tio3 ba al1 2sb1 2 o3 solid solution ceramics
Applied Physics Letters, 2009Co-Authors: Yuji HirumaAbstract:A solid-solution system, (1−x)(Bi1/2Na1/2)TiO3–xBa(Al1/2Sb1/2)O3 (BNT-BAS100x), was fabricated by a conventional ceramic fabrication process. The morphotropic phase boundary (MPB) between rhombohedral and pseudocubic phases of BNT-BAS100x was clarified to be at approximately x=0.045, and the highest normalized strain d33* of 532 pm/V was obtained at this Composition. This study also revealed that the MPB Composition of a BNT-based solid solution shifts to a BNT-Rich Composition as the tolerance factor t of the end member increases, and t of the MPB Composition is always approximately 0.983. This indicates that the MPB position can be predicted from t values of the end members.A solid-solution system, (1−x)(Bi1/2Na1/2)TiO3–xBa(Al1/2Sb1/2)O3 (BNT-BAS100x), was fabricated by a conventional ceramic fabrication process. The morphotropic phase boundary (MPB) between rhombohedral and pseudocubic phases of BNT-BAS100x was clarified to be at approximately x=0.045, and the highest normalized strain d33* of 532 pm/V was obtained at this Composition. This study also revealed that the MPB Composition of a BNT-based solid solution shifts to a BNT-Rich Composition as the tolerance factor t of the end member increases, and t of the MPB Composition is always approximately 0.983. This indicates that the MPB position can be predicted from t values of the end members.
-
detection of morphotropic phase boundary of bi1 2na1 2 tio3 ba al1 2sb1 2 o3 solid solution ceramics
Applied Physics Letters, 2009Co-Authors: Yuji Hiruma, Hajime Nagata, Tadashi TakenakaAbstract:A solid-solution system, (1−x)(Bi1/2Na1/2)TiO3–xBa(Al1/2Sb1/2)O3 (BNT-BAS100x), was fabricated by a conventional ceramic fabrication process. The morphotropic phase boundary (MPB) between rhombohedral and pseudocubic phases of BNT-BAS100x was clarified to be at approximately x=0.045, and the highest normalized strain d33* of 532 pm/V was obtained at this Composition. This study also revealed that the MPB Composition of a BNT-based solid solution shifts to a BNT-Rich Composition as the tolerance factor t of the end member increases, and t of the MPB Composition is always approximately 0.983. This indicates that the MPB position can be predicted from t values of the end members.
Nancy J Dudney - One of the best experts on this subject based on the ideXlab platform.
-
surface studies of high voltage lithium Rich Composition li1 2mn0 525ni0 175co0 1o2
Journal of Power Sources, 2012Co-Authors: Surendra K Martha, Jagjit Nanda, Gabriel M Veith, Nancy J DudneyAbstract:This article reports the evidence of surface film formation because of the breakdown of electrolyte upon high voltage cycling (4.9 V) of lithium Rich cathode having a nominal Composition of, Li1.2Mn0.525Ni0.175Co0.1O2. We studied the chemical Composition of this passivation film using electrochemical impedance, X-ray Photoelectron and micro-Raman spectroscopy and the results were compared against the pristine electrode. In order to distinguish the changes in the surface films Composition induced by prolonged electrochemical cycling versus chemical passivation effect, we also studied the surface Composition of cathode powders aged with electrolytes at 60 oC. Our study shows that electrodes cycled beyond 150 cycles showed a rapid drop in capacity due to increase in the surface film resistance resulting in limited capacity utilization.
-
electrochemical and rate performance study of high voltage lithium Rich Composition li1 2mn0 525ni0 175co0 1o2
Journal of Power Sources, 2012Co-Authors: Surendra K Martha, Jagjit Nanda, Gabriel M Veith, Nancy J DudneyAbstract:Abstract We report electrochemical studies of high voltage cathodes composed of lithium Rich “layered-layered” material having the nominal Composition Li 1.2 Mn 0.525 Ni 0.175 Co 0.1 O 2 , or equivalently 0.6Li[Li 1/3 Mn 2/3 ]O 2 –0.4Li[Mn 0.3 Ni 0.45 Co 0.25 ]O 2 . These aspects were investigated by cyclic voltammetry studies in conjunction with electrochemical impedance spectroscopy measurements to understand the redox reactions involving multiple transition metals and their capacity contribution at higher voltages, up to 4.9 V. Further, cathodes with 1.5 wt.% carbon nanofibers added to the Li 1.2 Mn 0.525 Ni 0.175 Co 0.1 O 2 composite electrode showed stable reversible capacities of about 280 mAh g −1 when cycled to 4.9 V for more than 100 cycles, and almost a factor of two improvements in the rate performance compared to the electrode Composition prepared using conventional Composition (7.5% carbon black and 7.5% binder).
Tadashi Takenaka - One of the best experts on this subject based on the ideXlab platform.
-
detection of morphotropic phase boundary of bi1 2na1 2 tio3 ba al1 2sb1 2 o3 solid solution ceramics
Applied Physics Letters, 2009Co-Authors: Yuji Hiruma, Hajime Nagata, Tadashi TakenakaAbstract:A solid-solution system, (1−x)(Bi1/2Na1/2)TiO3–xBa(Al1/2Sb1/2)O3 (BNT-BAS100x), was fabricated by a conventional ceramic fabrication process. The morphotropic phase boundary (MPB) between rhombohedral and pseudocubic phases of BNT-BAS100x was clarified to be at approximately x=0.045, and the highest normalized strain d33* of 532 pm/V was obtained at this Composition. This study also revealed that the MPB Composition of a BNT-based solid solution shifts to a BNT-Rich Composition as the tolerance factor t of the end member increases, and t of the MPB Composition is always approximately 0.983. This indicates that the MPB position can be predicted from t values of the end members.
Surendra K Martha - One of the best experts on this subject based on the ideXlab platform.
-
surface studies of high voltage lithium Rich Composition li1 2mn0 525ni0 175co0 1o2
Journal of Power Sources, 2012Co-Authors: Surendra K Martha, Jagjit Nanda, Gabriel M Veith, Nancy J DudneyAbstract:This article reports the evidence of surface film formation because of the breakdown of electrolyte upon high voltage cycling (4.9 V) of lithium Rich cathode having a nominal Composition of, Li1.2Mn0.525Ni0.175Co0.1O2. We studied the chemical Composition of this passivation film using electrochemical impedance, X-ray Photoelectron and micro-Raman spectroscopy and the results were compared against the pristine electrode. In order to distinguish the changes in the surface films Composition induced by prolonged electrochemical cycling versus chemical passivation effect, we also studied the surface Composition of cathode powders aged with electrolytes at 60 oC. Our study shows that electrodes cycled beyond 150 cycles showed a rapid drop in capacity due to increase in the surface film resistance resulting in limited capacity utilization.
-
electrochemical and rate performance study of high voltage lithium Rich Composition li1 2mn0 525ni0 175co0 1o2
Journal of Power Sources, 2012Co-Authors: Surendra K Martha, Jagjit Nanda, Gabriel M Veith, Nancy J DudneyAbstract:Abstract We report electrochemical studies of high voltage cathodes composed of lithium Rich “layered-layered” material having the nominal Composition Li 1.2 Mn 0.525 Ni 0.175 Co 0.1 O 2 , or equivalently 0.6Li[Li 1/3 Mn 2/3 ]O 2 –0.4Li[Mn 0.3 Ni 0.45 Co 0.25 ]O 2 . These aspects were investigated by cyclic voltammetry studies in conjunction with electrochemical impedance spectroscopy measurements to understand the redox reactions involving multiple transition metals and their capacity contribution at higher voltages, up to 4.9 V. Further, cathodes with 1.5 wt.% carbon nanofibers added to the Li 1.2 Mn 0.525 Ni 0.175 Co 0.1 O 2 composite electrode showed stable reversible capacities of about 280 mAh g −1 when cycled to 4.9 V for more than 100 cycles, and almost a factor of two improvements in the rate performance compared to the electrode Composition prepared using conventional Composition (7.5% carbon black and 7.5% binder).
Takaya Terashima - One of the best experts on this subject based on the ideXlab platform.
-
fluorous gradient copolymers via in situ transesterification of a perfluoromethacrylate in tandem living radical polymerization precision synthesis and physical properties
Macromolecules, 2018Co-Authors: Yusuke Ogura, Mikihito Takenaka, Mitsuo Sawamoto, Takaya TerashimaAbstract:Perfluorinated gradient copolymers comprising fluorous units and hydrophobic or hydrophilic units were created as fluorous polymer materials with unique physical properties. The gradient copolymers were efficiently synthesized via the tandem catalysis of living radical polymerization and titanium alkoxide-mediated transesterification of 1H,1H,2H,2H-perfluorooctyl methacrylate (13FOMA) with alcohols. Owing to the electron-withdrawing perfluorooctyl unit, 13FOMA was efficiently transesterified into another methacrylate (RMA) with alcohols during the copolymerization of 13FOMA and RMA to afford well-controlled 13FOMA/RMA gradient copolymers. The gradient sequence gradually changed from 13FOMA to RMA-Rich Composition according to monomer Composition varying in the polymerization solutions. The tandem catalysis is allowed to use various alcohols including 1-dodecanol, 1-octadecanol, ethanol, and poly(ethylene glycol) methyl ether; the catalysis developed herein is thus one of the most versatile systems to prod...
-
Fluorous Gradient Copolymers via in-Situ Transesterification of a Perfluoromethacrylate in Tandem Living Radical Polymerization: Precision Synthesis and Physical Properties
2018Co-Authors: Yusuke Ogura, Mikihito Takenaka, Mitsuo Sawamoto, Takaya TerashimaAbstract:Perfluorinated gradient copolymers comprising fluorous units and hydrophobic or hydrophilic units were created as fluorous polymer materials with unique physical properties. The gradient copolymers were efficiently synthesized via the tandem catalysis of living radical polymerization and titanium alkoxide-mediated transesterification of 1H,1H,2H,2H-perfluorooctyl methacrylate (13FOMA) with alcohols. Owing to the electron-withdrawing perfluorooctyl unit, 13FOMA was efficiently transesterified into another methacrylate (RMA) with alcohols during the copolymerization of 13FOMA and RMA to afford well-controlled 13FOMA/RMA gradient copolymers. The gradient sequence gradually changed from 13FOMA to RMA-Rich Composition according to monomer Composition varying in the polymerization solutions. The tandem catalysis is allowed to use various alcohols including 1-dodecanol, 1-octadecanol, ethanol, and poly(ethylene glycol) methyl ether; the catalysis developed herein is thus one of the most versatile systems to produce fluorous/hydrophobic or fluorous/hydrophilic gradient copolymers. Additionally, physical properties of a fluorous/hydrophobic 13FOMA/dodecyl methacrylate gradient copolymer were investigated. The gradient copolymer exhibited broad glass transition temperature, microphase separation, self-assembly, surface tension, and water/oil repellency distinct from corresponding random or block counterparts
