High temperature superconducting tape and method of manufacture

Details High temperature superconducting tape and method of manufacture High temperature superconducting tape and method of manufacture

1998-07-09

2001-12-11

Sheehan, John (Department: 1742)

Superconductor technology: apparatus, material, process

Processes of producing or treating high temperature...

Process of making wire, tape, cable, coil, or fiber

C505S470000, C505S500000, C148S277000, C148S280000

Reexamination Certificate

active

06329325

ABSTRACT:

BRIEF DESCRIPTION OF THE INVENTION
This invention relates generally to a high-temperature superconducting (HTSg) tape and method of manufacture and more particularly to a nickel tape having a highly oriented HgBa
2
Ca
2
Cu
3
O
8+&dgr;
layer and to method of manufacture.
BACKGROUND OF THE INVENTION
Layers of superconducting cuprate materials Bi
2
Sr
2
Ca
n−1
Cu
n
O
y
(n=2 or 3) and Tl
2
Ba
2
Co
2
Cu
3
Oy and TlB
2
C
2
Cu
3
Oy have been formed as a thin film on Ag tape to provid superconducting tapes.
The newly discovered high-temperature superconducting (HTSg) compound, HgBa
2
Ca
2
Cu
3
O
8+&dgr;
(Hg-1223) displays the highest transition temperature (T
c
) of 134 K at ambient pressure or 164 K at ~30 GPa. It also exhibits a modest flux pinning strength which lies between those of YBa
2
Cu
3
O
7
(YBCO) and Bi
2
Sr
2
Ca
n−1
Cu
n
O
2n+4+&dgr;
(BSCCO) [or Tl
2
Ba
2
Ca
n−1
Cu
n
O
2n+4+&dgr;
(TBCCO)] with n =1, 2, 3, . . . , suggesting a possible high critical current density (J
c
) at 77 K due to its higher Tc. Indeed, epitaxial thin films of HgBa
2
CaCu
2
O
6+&dgr;
(Hg-1212), which have a T
c
~128 K and are homologous to Hg-1223, have been prepared and show a J
c
~10
6
A/cm
2
at 100 K, implying a J
c
~5×10
6
A/cm
2
at 77 K. Since Hg-1223 has a higher T
c
than Hg-1212, a J
c
≧5×10
6
A/cm
2
at 77 K may be achievable in Hg-1223. Given the superior superconducting properties, Hg-1223 is therefore a desirable HTSg material for conductors, such as tapes and wires. Unfortunately, Hg-1223 is difficult to form and the compound is chemically unstable with the loss of Hg and the associated degradation at temperatures above ~350° C. This makes it extremely difficult to align the CuO
2
-planes by the high-temperature melt-texturing technique commonly used for other HTSg materials. Added to the difficulty is the fact that the Hg released from the compound attacks many metals, especially at high temperatures, and forms amalgams.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a highly oriented HgBa
2
Ca
2
Cu
3
O
8+&dgr;
(Hg-1223) tape and process for its manufacture.
It is a further object of the present invention to provide a tape comprising a thick film of Hg-1223 attached to a nickel tape via a thin Cr/Ag or Cr/(Ag—Pd) buffer layer.
It is another object of the present invention to provide highly oriented HgBa
2
Ca
2
Cu
3
O
8+&dgr;
on Ni-tape with a buffer layer of Cr/Ag or Cr/(Ag—Pd) and to a method of manufacture.
There is provided a high temperature superconducting (HTSg) tape comprising a nickel tape covered with a Cr/Ag or Cr/(Ag—Pd) buffer layer onto which a thick highly oriented HgBa
2
Ca
2
Cu
3
O
8+&dgr;
layer is formed and to a method of manufacture.


REFERENCES:
patent: 5071828 (1991-12-01), Greuter et al.
patent: 5462921 (1995-10-01), Adacht et al.
patent: 5578551 (1996-11-01), Chu et al.
patent: 5599775 (1997-02-01), Itoh et al.
patent: 5652199 (1997-07-01), Isawa et al.
patent: 5858926 (1999-01-01), Schwartz et al.
patent: 5883050 (1999-03-01), Yun et al.
Wang, et al.; Synthesis of preferred-oriented HgBa2Ca2Cu2O8+&dgr;thin films; Appl. Phys. Lett. 63; Nov., 1993 pp. 3084-3086.
Meng, et al. Synthesis of the high-temperature superconductors HgBa2Ca2Cu2O8+&dgr;and HgBa2Ca2Cu3O8+&dgr;; Physica C Superconductivity; Phisica C216 (1993) 21-28. (No month data).

Affiliated with

Also associated with

Rating

High temperature superconducting tape and method of manufacture does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with High temperature superconducting tape and method of manufacture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High temperature superconducting tape and method of manufacture will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2571669