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Toshikazu Takada - One of the best experts on this subject based on the ideXlab platform.
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missing orbital analysis on hyperpolarizability β of organic molecules enhancement of the off Diagonal Component βzxx using multiple substitutions
Chemical Physics Letters, 1995Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract The first-order hyperpolarizability Components, βzzz and βzxx, for C2v molecules (the z axis being the principal axis) are analyzed after simplified sum-over-states calculations. Compared with p-nitroaniline (PNA), βzxx is three times enhanced by x-extended π conjugation realized by a bulky substrate in 9-amino-10-nitroanthracene (ANA) and by multiple substitutions in 1,5-diamino-2,4-dinitrobenzene (DDB). While ANA shows βzzz unchanged because its z-directed charge transfer (CT) is similar to PNA, DDB has a β zzz 1 3 of PNA, which is reduced by two weak CTs introduced by two ortho-positioned donor-acceptor pairs on both sides of the z axis.
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Missing-orbital analysis of molecular hyperpolarizability β calculated by a simplified sum-over-states method: “multi-state” model for βzxx
Journal of Molecular Structure, 1994Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract Missing-orbital analysis is applied to the Diagonal and off-Diagonal Components of the first-order hyperpolarizability tensor β evaluated by a simplified sum-over-states method. Various molecules assumed to have C2v symmetry are examined: benzene, pyridine-oxide and polyynes substituted with amino and either cyano or nitro groups. The missing-orbital analysis shows that the Diagonal Component βzzz (z-axis in the donor-to-acceptor direction) for most of the molecules is essentially dominated by only one strongly charge-transfer excited configuration, and is describable by the conventional two-state model. For the off-Diagonal Component βzxx, it is revealed that the excitations from a2 and b2 orbitals cooperatively make an important contribution. This indicates that, even for the molecules whose βzzz is described well by the two-state model, βzxx is necessarily modeled by a “multi-state” model consisting of the ground state and at least two excited configurations belonging to two different symmetries.
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Missing-orbital analysis of molecular hyperpolarizability β calculated by a simplified sum-over-states method. Enhancement of the off-Diagonal Component βzxx
Chemical Physics Letters, 1993Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract The off-Diagonal Component of the first-order hyperpolarizability tensor βzxx of C2v molecules, e.g. substituted polyynes and benzenes, has been calculated by a simplified sum-over-states method. The missing-orbital analysis of the calcualted results reveals that excitations from a2 and b2 orbitals contribute cooperatively to βzxx, suggesting an insufficiency of the two-state model to describe βzxx. Increasing the number of occupied a2 orbitals enhances the magnitude of βzxx. For the C2v molecule with a2 orbitals widely extended in the x direction, βzxx can exceed βzzz, as found in 9-amino-10-cyanoanthracene having a βzxx about twice as large as βzzz.
F Terki - One of the best experts on this subject based on the ideXlab platform.
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Planar Hall resistance ring sensor based on NiFe/Cu/IrMn trilayer structure
Journal of Applied Physics, 2013Co-Authors: Brajalal Sinha, Tran Quang Hung, T S Ramulu, F Terki, Kunwoo Kim, Dong Young Kim, Cheolgi KimAbstract:We have investigated the sensitivity of a planar Hall resistance sensor as a function of the ring radius in the trilayer structure Ta(3)/IrMn(10)/Cu(0.2)/NiFe(10)/Ta(3) (nm). The Diagonal Components of magnetoresistivity tensor in rectangular prism corresponding to anisotropic magnetoresistance are few ten times larger than that of off-Diagonal Component corresponding to planar Hall resistance. However, it is noteworthy that the resultant contribution is governed by the off-Diagonal Components due to the cancellation of Diagonal Components in the self-balanced bridge configuration. Both the experimental and theoretical results show that the sensitivity varies linearly with the ring radius. In multi-ring architecture, the circumference can be increased to a limit, which consequently enhances sensitivity. We found the sensitivity of the investigated 7-rings planar Hall to be more than 600 μV/Oe.
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planar hall resistance ring sensor based on nife cu irmn trilayer structure
Journal of Applied Physics, 2013Co-Authors: Brajalal Sinha, Tran Quang Hung, T S Ramulu, Sunjong Oh, F TerkiAbstract:We have investigated the sensitivity of a planar Hall resistance sensor as a function of the ring radius in the trilayer structure Ta(3)/IrMn(10)/Cu(0.2)/NiFe(10)/Ta(3) (nm). The Diagonal Components of magnetoresistivity tensor in rectangular prism corresponding to anisotropic magnetoresistance are few ten times larger than that of off-Diagonal Component corresponding to planar Hall resistance. However, it is noteworthy that the resultant contribution is governed by the off-Diagonal Components due to the cancellation of Diagonal Components in the self-balanced bridge configuration. Both the experimental and theoretical results show that the sensitivity varies linearly with the ring radius. In multi-ring architecture, the circumference can be increased to a limit, which consequently enhances sensitivity. We found the sensitivity of the investigated 7-rings planar Hall to be more than 600 μV/Oe.
Mutsumi Tomonari - One of the best experts on this subject based on the ideXlab platform.
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missing orbital analysis on hyperpolarizability β of organic molecules enhancement of the off Diagonal Component βzxx using multiple substitutions
Chemical Physics Letters, 1995Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract The first-order hyperpolarizability Components, βzzz and βzxx, for C2v molecules (the z axis being the principal axis) are analyzed after simplified sum-over-states calculations. Compared with p-nitroaniline (PNA), βzxx is three times enhanced by x-extended π conjugation realized by a bulky substrate in 9-amino-10-nitroanthracene (ANA) and by multiple substitutions in 1,5-diamino-2,4-dinitrobenzene (DDB). While ANA shows βzzz unchanged because its z-directed charge transfer (CT) is similar to PNA, DDB has a β zzz 1 3 of PNA, which is reduced by two weak CTs introduced by two ortho-positioned donor-acceptor pairs on both sides of the z axis.
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Missing-orbital analysis of molecular hyperpolarizability β calculated by a simplified sum-over-states method: “multi-state” model for βzxx
Journal of Molecular Structure, 1994Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract Missing-orbital analysis is applied to the Diagonal and off-Diagonal Components of the first-order hyperpolarizability tensor β evaluated by a simplified sum-over-states method. Various molecules assumed to have C2v symmetry are examined: benzene, pyridine-oxide and polyynes substituted with amino and either cyano or nitro groups. The missing-orbital analysis shows that the Diagonal Component βzzz (z-axis in the donor-to-acceptor direction) for most of the molecules is essentially dominated by only one strongly charge-transfer excited configuration, and is describable by the conventional two-state model. For the off-Diagonal Component βzxx, it is revealed that the excitations from a2 and b2 orbitals cooperatively make an important contribution. This indicates that, even for the molecules whose βzzz is described well by the two-state model, βzxx is necessarily modeled by a “multi-state” model consisting of the ground state and at least two excited configurations belonging to two different symmetries.
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Missing-orbital analysis of molecular hyperpolarizability β calculated by a simplified sum-over-states method. Enhancement of the off-Diagonal Component βzxx
Chemical Physics Letters, 1993Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract The off-Diagonal Component of the first-order hyperpolarizability tensor βzxx of C2v molecules, e.g. substituted polyynes and benzenes, has been calculated by a simplified sum-over-states method. The missing-orbital analysis of the calcualted results reveals that excitations from a2 and b2 orbitals contribute cooperatively to βzxx, suggesting an insufficiency of the two-state model to describe βzxx. Increasing the number of occupied a2 orbitals enhances the magnitude of βzxx. For the C2v molecule with a2 orbitals widely extended in the x direction, βzxx can exceed βzzz, as found in 9-amino-10-cyanoanthracene having a βzxx about twice as large as βzzz.
Brajalal Sinha - One of the best experts on this subject based on the ideXlab platform.
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Planar Hall resistance ring sensor based on NiFe/Cu/IrMn trilayer structure
Journal of Applied Physics, 2013Co-Authors: Brajalal Sinha, Tran Quang Hung, T S Ramulu, F Terki, Kunwoo Kim, Dong Young Kim, Cheolgi KimAbstract:We have investigated the sensitivity of a planar Hall resistance sensor as a function of the ring radius in the trilayer structure Ta(3)/IrMn(10)/Cu(0.2)/NiFe(10)/Ta(3) (nm). The Diagonal Components of magnetoresistivity tensor in rectangular prism corresponding to anisotropic magnetoresistance are few ten times larger than that of off-Diagonal Component corresponding to planar Hall resistance. However, it is noteworthy that the resultant contribution is governed by the off-Diagonal Components due to the cancellation of Diagonal Components in the self-balanced bridge configuration. Both the experimental and theoretical results show that the sensitivity varies linearly with the ring radius. In multi-ring architecture, the circumference can be increased to a limit, which consequently enhances sensitivity. We found the sensitivity of the investigated 7-rings planar Hall to be more than 600 μV/Oe.
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planar hall resistance ring sensor based on nife cu irmn trilayer structure
Journal of Applied Physics, 2013Co-Authors: Brajalal Sinha, Tran Quang Hung, T S Ramulu, Sunjong Oh, F TerkiAbstract:We have investigated the sensitivity of a planar Hall resistance sensor as a function of the ring radius in the trilayer structure Ta(3)/IrMn(10)/Cu(0.2)/NiFe(10)/Ta(3) (nm). The Diagonal Components of magnetoresistivity tensor in rectangular prism corresponding to anisotropic magnetoresistance are few ten times larger than that of off-Diagonal Component corresponding to planar Hall resistance. However, it is noteworthy that the resultant contribution is governed by the off-Diagonal Components due to the cancellation of Diagonal Components in the self-balanced bridge configuration. Both the experimental and theoretical results show that the sensitivity varies linearly with the ring radius. In multi-ring architecture, the circumference can be increased to a limit, which consequently enhances sensitivity. We found the sensitivity of the investigated 7-rings planar Hall to be more than 600 μV/Oe.
Norio Ookubo - One of the best experts on this subject based on the ideXlab platform.
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missing orbital analysis on hyperpolarizability β of organic molecules enhancement of the off Diagonal Component βzxx using multiple substitutions
Chemical Physics Letters, 1995Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract The first-order hyperpolarizability Components, βzzz and βzxx, for C2v molecules (the z axis being the principal axis) are analyzed after simplified sum-over-states calculations. Compared with p-nitroaniline (PNA), βzxx is three times enhanced by x-extended π conjugation realized by a bulky substrate in 9-amino-10-nitroanthracene (ANA) and by multiple substitutions in 1,5-diamino-2,4-dinitrobenzene (DDB). While ANA shows βzzz unchanged because its z-directed charge transfer (CT) is similar to PNA, DDB has a β zzz 1 3 of PNA, which is reduced by two weak CTs introduced by two ortho-positioned donor-acceptor pairs on both sides of the z axis.
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Missing-orbital analysis of molecular hyperpolarizability β calculated by a simplified sum-over-states method: “multi-state” model for βzxx
Journal of Molecular Structure, 1994Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract Missing-orbital analysis is applied to the Diagonal and off-Diagonal Components of the first-order hyperpolarizability tensor β evaluated by a simplified sum-over-states method. Various molecules assumed to have C2v symmetry are examined: benzene, pyridine-oxide and polyynes substituted with amino and either cyano or nitro groups. The missing-orbital analysis shows that the Diagonal Component βzzz (z-axis in the donor-to-acceptor direction) for most of the molecules is essentially dominated by only one strongly charge-transfer excited configuration, and is describable by the conventional two-state model. For the off-Diagonal Component βzxx, it is revealed that the excitations from a2 and b2 orbitals cooperatively make an important contribution. This indicates that, even for the molecules whose βzzz is described well by the two-state model, βzxx is necessarily modeled by a “multi-state” model consisting of the ground state and at least two excited configurations belonging to two different symmetries.
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Missing-orbital analysis of molecular hyperpolarizability β calculated by a simplified sum-over-states method. Enhancement of the off-Diagonal Component βzxx
Chemical Physics Letters, 1993Co-Authors: Mutsumi Tomonari, Norio Ookubo, Toshikazu TakadaAbstract:Abstract The off-Diagonal Component of the first-order hyperpolarizability tensor βzxx of C2v molecules, e.g. substituted polyynes and benzenes, has been calculated by a simplified sum-over-states method. The missing-orbital analysis of the calcualted results reveals that excitations from a2 and b2 orbitals contribute cooperatively to βzxx, suggesting an insufficiency of the two-state model to describe βzxx. Increasing the number of occupied a2 orbitals enhances the magnitude of βzxx. For the C2v molecule with a2 orbitals widely extended in the x direction, βzxx can exceed βzzz, as found in 9-amino-10-cyanoanthracene having a βzxx about twice as large as βzzz.