Electricity: measuring and testing – Determining nonelectric properties by measuring electric... – Superconductors
Patent
1993-01-28
1994-08-16
Wieder, Kenneth A.
Electricity: measuring and testing
Determining nonelectric properties by measuring electric...
Superconductors
324713, 505843, G01N 2700
Patent
active
053390253
ABSTRACT:
The present invention provides a method for determining the granular nature of superconductive materials and devices which includes the steps of: conducting a substantially rectangular current pulse through the superconductive material, maintaining the temperature of the superconductive material at a substantially constant temperature which does not exceed the critical temperature of the superconductive material; determining the amplitude of the current pulse; determining the electrical resistance, R, of the superconductive material resulting from conducting current pulse through the superconductive material; increasing the current until the electrical resistance of the superconductive material becomes saturated; determining the electrical resistance difference, .delta., between the electrical resistance, R, of the saturated superconductive material and a total normal state electrical resistance of the superconductive material; generating a first output signal if .vertline..delta..vertline..ltoreq..epsilon., where .epsilon. represents a predetermined limit, where the first output signal corresponds to the superconductive material having a homogenous microscopic morphology; and generating a second output signal if .vertline..delta..vertline.>.epsilon., where the second output signal corresponds to the superconductive material having a granular morphology. The method may also be used to determine the saturated electrical resistances of the superconductive sample.
REFERENCES:
patent: 3390330 (1968-06-01), Meyerhoff et al.
patent: 3428891 (1969-02-01), Purcell et al.
patent: 4213087 (1980-07-01), English et al.
patent: 4777437 (1988-10-01), Tashiro et al.
patent: 4904929 (1990-02-01), Bohandy et al.
patent: 4947118 (1990-08-01), Fujimaki
patent: 5065087 (1991-11-01), Kita et al.
patent: 5134360 (1992-07-01), Martin et al,
patent: 5223798 (1993-06-01), McGinnis et al.
"Critical Current Measurements on Yb-Ba-Cu-O" by T. E. Jones et al., Matels Research Society Extended Abstracts, High Temperature Superconductors, Proceedings of Symposium S, Apr. 1987, pp. 235-237.
"Pulsed Current Measurement of the Resistive Transition and Critical Current in High T.sub.c Superconductors" by W. C. McGinnis et al.; Rev. Sci. Instrum. 61(3) Mar. 1990, pp. 984-987.
"Critical Currents and Current-Voltage Characteristics in Superconducting Ceramic YBa.sub.2 Cu.sub.3 O.sub.7 " by Dan Goldschmidt, Physical Review, vol. 39, No. 13, May 1, 1989, pp. 9139-9146.
"Critical Current Densities For the High Temperature Ceramic Superconductors YBa.sub.2 Cu.sub.3 O.sub.7 and Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 " by W. C. McGinnis et al., IEEE Transactions on Magnetics, vol. 25, No. 2, Mar. 1989, pp. 2138-2141.
Jones Thomas E.
McGinnis Wayne C.
Fendelman Harvey
Kagan Michael A.
Keough Thomas Glenn
The United States of America as represented by the Secretary of
Tobin Christopher M.
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