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Hideo Hosono - One of the best experts on this subject based on the ideXlab platform.
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advantageous grain boundaries in iron pnictide superconductors
Nature Communications, 2011Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries-the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined Bicrystal grain boundary junctions with various misorientation angles (θ(GB)) were systematically investigated for cobalt-doped BaFe(2)As(2) (BaFe(2)As(2):Co) epitaxial films fabricated on Bicrystal substrates. The critical current density through Bicrystal grain boundary (J(c)(BGB)) remained high (>1 MA cm(-2)) and nearly constant up to a critical angle θ(c) of ∼9°, which is substantially larger than the θ(c) of ∼5° for YBa(2)Cu(3)O(7-δ). Even at θ(GB)>θ(c), the decay of J(c)(BGB) was much slower than that of YBa(2)Cu(3)O(7-δ).
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dc superconducting quantum interference devices fabricated using Bicrystal grain boundary junctions in co doped bafe2as2 epitaxial films
Superconductor Science and Technology, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:DC superconducting quantum interference devices (dc-SQUIDs) were fabricated in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 Bicrystal substrates with 30° misorientation angles. The 18 × 8 µm2 SQUID loop with an estimated inductance of 13 pH contained two 3 µm wide grain boundary junctions. The voltage–flux characteristics clearly exhibited periodic modulations with ΔV = 1.4 µV at 14 K, while the intrinsic flux noise of dc-SQUIDs was 7.8 × 10 − 5 Φ0 Hz − 1/2 above 20 Hz. The rather high flux noise is mainly attributed to the small voltage modulation depth which results from the superconductor–normal-metal–superconductor junction nature of the Bicrystal grain boundary.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
Applied Physics Letters, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10-μm-wide microbridges spanning a 30°-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current–voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
arXiv: Superconductivity, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
Takayoshi Katase - One of the best experts on this subject based on the ideXlab platform.
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advantageous grain boundaries in iron pnictide superconductors
Nature Communications, 2011Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries-the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined Bicrystal grain boundary junctions with various misorientation angles (θ(GB)) were systematically investigated for cobalt-doped BaFe(2)As(2) (BaFe(2)As(2):Co) epitaxial films fabricated on Bicrystal substrates. The critical current density through Bicrystal grain boundary (J(c)(BGB)) remained high (>1 MA cm(-2)) and nearly constant up to a critical angle θ(c) of ∼9°, which is substantially larger than the θ(c) of ∼5° for YBa(2)Cu(3)O(7-δ). Even at θ(GB)>θ(c), the decay of J(c)(BGB) was much slower than that of YBa(2)Cu(3)O(7-δ).
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dc superconducting quantum interference devices fabricated using Bicrystal grain boundary junctions in co doped bafe2as2 epitaxial films
Superconductor Science and Technology, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:DC superconducting quantum interference devices (dc-SQUIDs) were fabricated in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 Bicrystal substrates with 30° misorientation angles. The 18 × 8 µm2 SQUID loop with an estimated inductance of 13 pH contained two 3 µm wide grain boundary junctions. The voltage–flux characteristics clearly exhibited periodic modulations with ΔV = 1.4 µV at 14 K, while the intrinsic flux noise of dc-SQUIDs was 7.8 × 10 − 5 Φ0 Hz − 1/2 above 20 Hz. The rather high flux noise is mainly attributed to the small voltage modulation depth which results from the superconductor–normal-metal–superconductor junction nature of the Bicrystal grain boundary.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
Applied Physics Letters, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10-μm-wide microbridges spanning a 30°-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current–voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
arXiv: Superconductivity, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
Yoshihiro Ishimaru - One of the best experts on this subject based on the ideXlab platform.
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advantageous grain boundaries in iron pnictide superconductors
Nature Communications, 2011Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries-the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined Bicrystal grain boundary junctions with various misorientation angles (θ(GB)) were systematically investigated for cobalt-doped BaFe(2)As(2) (BaFe(2)As(2):Co) epitaxial films fabricated on Bicrystal substrates. The critical current density through Bicrystal grain boundary (J(c)(BGB)) remained high (>1 MA cm(-2)) and nearly constant up to a critical angle θ(c) of ∼9°, which is substantially larger than the θ(c) of ∼5° for YBa(2)Cu(3)O(7-δ). Even at θ(GB)>θ(c), the decay of J(c)(BGB) was much slower than that of YBa(2)Cu(3)O(7-δ).
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dc superconducting quantum interference devices fabricated using Bicrystal grain boundary junctions in co doped bafe2as2 epitaxial films
Superconductor Science and Technology, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:DC superconducting quantum interference devices (dc-SQUIDs) were fabricated in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 Bicrystal substrates with 30° misorientation angles. The 18 × 8 µm2 SQUID loop with an estimated inductance of 13 pH contained two 3 µm wide grain boundary junctions. The voltage–flux characteristics clearly exhibited periodic modulations with ΔV = 1.4 µV at 14 K, while the intrinsic flux noise of dc-SQUIDs was 7.8 × 10 − 5 Φ0 Hz − 1/2 above 20 Hz. The rather high flux noise is mainly attributed to the small voltage modulation depth which results from the superconductor–normal-metal–superconductor junction nature of the Bicrystal grain boundary.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
Applied Physics Letters, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10-μm-wide microbridges spanning a 30°-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current–voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
arXiv: Superconductivity, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
Keiichi Tanabe - One of the best experts on this subject based on the ideXlab platform.
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advantageous grain boundaries in iron pnictide superconductors
Nature Communications, 2011Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries-the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined Bicrystal grain boundary junctions with various misorientation angles (θ(GB)) were systematically investigated for cobalt-doped BaFe(2)As(2) (BaFe(2)As(2):Co) epitaxial films fabricated on Bicrystal substrates. The critical current density through Bicrystal grain boundary (J(c)(BGB)) remained high (>1 MA cm(-2)) and nearly constant up to a critical angle θ(c) of ∼9°, which is substantially larger than the θ(c) of ∼5° for YBa(2)Cu(3)O(7-δ). Even at θ(GB)>θ(c), the decay of J(c)(BGB) was much slower than that of YBa(2)Cu(3)O(7-δ).
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dc superconducting quantum interference devices fabricated using Bicrystal grain boundary junctions in co doped bafe2as2 epitaxial films
Superconductor Science and Technology, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:DC superconducting quantum interference devices (dc-SQUIDs) were fabricated in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 Bicrystal substrates with 30° misorientation angles. The 18 × 8 µm2 SQUID loop with an estimated inductance of 13 pH contained two 3 µm wide grain boundary junctions. The voltage–flux characteristics clearly exhibited periodic modulations with ΔV = 1.4 µV at 14 K, while the intrinsic flux noise of dc-SQUIDs was 7.8 × 10 − 5 Φ0 Hz − 1/2 above 20 Hz. The rather high flux noise is mainly attributed to the small voltage modulation depth which results from the superconductor–normal-metal–superconductor junction nature of the Bicrystal grain boundary.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
Applied Physics Letters, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10-μm-wide microbridges spanning a 30°-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current–voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
arXiv: Superconductivity, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
Hidenori Hiramatsu - One of the best experts on this subject based on the ideXlab platform.
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advantageous grain boundaries in iron pnictide superconductors
Nature Communications, 2011Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries-the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined Bicrystal grain boundary junctions with various misorientation angles (θ(GB)) were systematically investigated for cobalt-doped BaFe(2)As(2) (BaFe(2)As(2):Co) epitaxial films fabricated on Bicrystal substrates. The critical current density through Bicrystal grain boundary (J(c)(BGB)) remained high (>1 MA cm(-2)) and nearly constant up to a critical angle θ(c) of ∼9°, which is substantially larger than the θ(c) of ∼5° for YBa(2)Cu(3)O(7-δ). Even at θ(GB)>θ(c), the decay of J(c)(BGB) was much slower than that of YBa(2)Cu(3)O(7-δ).
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dc superconducting quantum interference devices fabricated using Bicrystal grain boundary junctions in co doped bafe2as2 epitaxial films
Superconductor Science and Technology, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:DC superconducting quantum interference devices (dc-SQUIDs) were fabricated in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 Bicrystal substrates with 30° misorientation angles. The 18 × 8 µm2 SQUID loop with an estimated inductance of 13 pH contained two 3 µm wide grain boundary junctions. The voltage–flux characteristics clearly exhibited periodic modulations with ΔV = 1.4 µV at 14 K, while the intrinsic flux noise of dc-SQUIDs was 7.8 × 10 − 5 Φ0 Hz − 1/2 above 20 Hz. The rather high flux noise is mainly attributed to the small voltage modulation depth which results from the superconductor–normal-metal–superconductor junction nature of the Bicrystal grain boundary.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
Applied Physics Letters, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10-μm-wide microbridges spanning a 30°-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current–voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.
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josephson junction in cobalt doped bafe2as2 epitaxial thin films on la sr al ta o3 Bicrystal substrates
arXiv: Superconductivity, 2010Co-Authors: Takayoshi Katase, Yoshihiro Ishimaru, Akira Tsukamoto, Hidenori Hiramatsu, Toshio Kamiya, Keiichi Tanabe, Hideo HosonoAbstract:Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 Bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted Bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB.