公开(公告)号：JPH11111080A

公开(公告)日：1999-04-23

申请号：JP28315597

申请日：1997-10-01

Applicant: INT SUPERCONDUCTIVITY TECH ,  NGK INSULATORS LTD ,  CHUBU ELECTRIC POWER ,  HITACHI LTD

Inventor： ARAI YUSUKE ,  YAMADA YASUSHI ,  KAWASHIMA JUNICHI ,  BUN TAKEKUNI ,  HIRABAYASHI IZUMI ,  KOSHIZUKA NAOKI ,  HIGASHIYAMA KAZUHISA ,  FUJIWARA TETSUO

IPC: C01G1/00 ,  C01G3/00 ,  H01B12/06 ,  H01L39/02

Abstract: PROBLEM TO BE SOLVED: To improve critical current density in a magnetic field by the introduction of low inclination grain boundaries into a superconducting oxide film by forming a biaxially oriented superconducting oxide film on a metallic silver substrate having a 100} texture. SOLUTION: An oxide intermediate layer biaxially oriented in a substrate plane, a parallel plane of a substrate is proper in 100}, and magnesium oxide MgO is used as a material. When a lattice miss fit of oxide and superconducting oxide of this intermediate layer is high like 6 to 11%. The superconducting oxide growing on the oxide of the intermediate layer performs pseudo epitaxial growth having fluctuation in in-plane orientation. Due to this fluctuation, low inclination grain boundaries less than one degree of an inclination of a degree of not interrupting a path of a superconducting current, are generated in large numbers in a C axis oriented superconducting oxide film manufactured on the oxide of the intermediate layer. Since these low inclination grain boundaries operate as pin fastening points to trap a magnetic field, high critical current density in the magnetic field can be realized.

公开(公告)号：JPH11112044A

公开(公告)日：1999-04-23

申请号：JP26580097

申请日：1997-09-30

Applicant: INT SUPERCONDUCTIVITY TECH ,  MITSUBISHI ELECTRIC CORP ,  NEC CORP

Inventor： YUYA NAOKI ,  SUZUKI KATSUMI ,  ENOMOTO YOICHI ,  BUN TAKEKUNI

IPC: H01L39/22 ,  H01L39/24

Abstract: PROBLEM TO BE SOLVED: To form a uniform joint with high reproducibility while suppressing fluctuation by machining a substrate into a desired shape by varying the irradiation quantity of a focused ion beam depending on the position of a groove made in the substrate such that the groove is shaped optimally for formation of the joint. SOLUTION: A thin metal film 8 is deposited an MgO substrate 1 and a joint forming part is irradiated with a Ga ion beam by means of a focused ion beam system. Machining is performed while varying ion irradiation in three steps at a beam pitch of 30 nm such that ion irradiation is maximized in the center of the groove thus forming the inclining part (regions a, b) of the groove 3 having a constant inclination angle over a wide range. Since the angle of the groove can be set optimally by varying ion irradiation and beam pitch depending on the position of the groove and the inclining face can be adjusted to have a constant angle, a uniform joint can be formed with high reproducibility while suppressing fluctuation.

公开(公告)号：JP2002009353A

公开(公告)日：2002-01-11

申请号：JP2000182223

申请日：2000-06-16

Applicant: INT SUPERCONDUCTIVITY TECH

Inventor： JULIJ ERUTSUEFU ,  NAKAO KOICHI ,  YAMADA YASUSHI ,  BUN TAKEKUNI ,  ENOMOTO YOICHI ,  HIRABAYASHI IZUMI ,  KOSHIZUKA NAOKI

IPC: C30B29/22 ,  H01B13/00 ,  H01L39/22 ,  H01L39/24

Abstract: PROBLEM TO BE SOLVED: To provide a high temperature Josephson junction element exhibiting critical current-magnetic field characteristics different from the Fraunhofer pattern of Josephson junction in the s-s wave junction of a metal based superconductor. SOLUTION: The high temperature Josephson junction element employs a bicrystal oxide superconductor where two grains forming the junction interface of a bicrystal oxide superconducting film 6 formed on a bicrystal substrate 3 are c-axis oriented grains and the boundary interfaces of these two grains are 110} face and 100} face or 010} face. Superconducting critical current exhibits a minimal value of substantially 0 under 0 magnetic field and repeats maximal and minimal values periodically as the absolute value of magnetic field increases.

公开(公告)号：JP2000264788A

公开(公告)日：2000-09-26

申请号：JP6600099

申请日：1999-03-12

Applicant: INT SUPERCONDUCTIVITY TECH ,  KOBE STEEL LTD

Inventor： TAKAGI TOSHIAKI ,  BUN TAKEKUNI ,  MACHI TAKAHITO ,  HASHIMOTO KENJI ,  TAKAHASHI YASUO ,  MORISHITA TADATAKA ,  HIRABAYASHI IZUMI ,  KOSHIZUKA NAOKI

IPC: C30B29/22 ,  C30B15/00 ,  C30B19/00 ,  C30B19/06 ,  H01L39/24

Abstract: PROBLEM TO BE SOLVED: To obtain a bicrystal oxide superconductive film free from sinuosity at the joining interface by forming a film having a long straight chain joining interface on a bicrystal substrate by a liquid phase growth method. SOLUTION: The length of the straight chain joining interface is >=1 μm. Starting materials forming an REBaCuO (RE is rate earth elements such as Y, Nd and Sm) type oxide superconductor are put in a furnace 1 and a bicrystal substrate 3 of MgO or the like with a thin film of a seed crystal formed on the surface is disposed just above the starting materials. The starting materials are melted by heating to form a melt 2, the substrate 3 which is slowly pulled up under rotation by a rotating shaft 5 is immersed in the surface of the melt and a crystal is grown on the substrate. The objective superconductive film having a joining interface at the same position as the substrate 3 and having the same joining tilt and (θ) as the substrate is formed on the substrate. An electronic device such as a switching element, a current limiting device or SQUID is obtained by using the superconductive film.

公开(公告)号：JP2000150974A

公开(公告)日：2000-05-30

申请号：JP16202599

申请日：1999-06-09

Applicant: NEC CORP ,  INT SUPERCONDUCTIVITY TECH

Inventor： SATO TETSURO ,  BUN TAKEKUNI ,  KOSHIZUKA NAOKI ,  TANAKA SHOJI

IPC: H01L39/22 ,  H01L39/24

Abstract: PROBLEM TO BE SOLVED: To provide a high-temperature superconducting Josephson junction which is uniform and excellent in characteristics by a method, wherein a barrier layer uniform in thickness and composition is formed keeping high in reproducibility. SOLUTION: This manufacturing method comprises a first step a first superconducting layer 2 is formed on a substrate 1, a second step where an insulating film 5 is formed on the first conducting layer 2, a third step where the insulating film 5 is etched so as to be provided with a slope, a fourth step where the first superconducting layer 2 is etched so as to be provided with a slope using the etched insulating film 5 as a mask, a fifth step where a barrier layer 3 is formed on the surface of the slope, and a sixth step where a second superconducting layer 4 is formed on the barrier layer 3 and the slope of the insulating layer 5.

公开(公告)号：JPH11340534A

公开(公告)日：1999-12-10

申请号：JP24809098

申请日：1998-09-02

Applicant: HITACHI LTD ,  INT SUPERCONDUCTIVITY TECH

Inventor： USAGAWA TOSHIYUKI ,  BUN TAKEKUNI ,  KOYAMA SATOSHI ,  UTAGAWA TADASHI ,  TANABE KEIICHI

IPC: H01L39/22 ,  H01L39/24

Abstract: PROBLEM TO BE SOLVED: To substantially remove a grain boundary in a Josephson junction, by jointing a superconducting body to a normal conducting body in the single crystal grain of a substrate to make the Josephson junction. SOLUTION: A Josephson junction is formed on the YBCO single-crystal region (oxide-based superconducting body) of a substrate formed in a plane, and superconducting wirings 5, 6 and taking-out parts 7, 8 are formed on the YBCO single-crystal region. That is, a YBCO single-crystal in cut away at a (110) crystal plane direction in a wafer shape to remove the incompleteness of a YBCO single-crystal substrate 20' doped at 3 to 14% Zn, a grain of YBCFO 31 is grown homoeptaxially, and then the superconducting wiring 5, a YBCO layer 21 and a PCB 22 (normal conducting body) to be the underlayer superconducting layer 21 of Josephson junctions 300, 301 are formed. Also, an interlayer separating film 40 is formed over the whole surface, and then contact holes 9 are formed in the Josephson junctions 300, 301 to form the superconcuting wiring 6.