2005 Fiscal Year Final Research Report Summary
SHOCK COMPACTION OF THE PARTICLES OF Bi-Pb-Sr-Ca-Cu-O SUPERCONDUCTOR
| Project/Area Number |
16560045
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied physics, general
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| Research Institution | Tokyo University of Technology |
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Principal Investigator |
KEZUKA Hiroshi TOKYO UNIVERSITY OF TECHNOLOGY, SCHOOL OF BIONICS, ASSOCIATE PROFESSOR, バイオニクス学部, 助教授 (20192049)
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| Project Period (FY) |
2004 – 2005
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| Keywords | magnetic sensor / Bi-Pb-Sr-Ca-Cu-O(BPSCCO) / magneto-resistance(GMR) / oxide-superconductor / magnetic sensitivity / shock compaction / 磁気抵抗 |
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| Research Abstract |
A magnetic sensor, constructed of bulk Bi-Pb-Sr-Ca-Cu-O(BPSCCO), was fabricated by use of the shock compaction method, employing a propellant gun-system, and then sintered under through use of an electronic furnace. The specimen as a magnetic sensor was maintained in the superconducting state at 77.4 K, under a current density J of approximately 40 A/cm^2 in the absence of an excitation magnetic field B_<ex>. The superconducting state was then broken and the specimen exposed to a B<ex> value of 40×10^<-4> T. That is, the resistance R_<meas> of the specimen occurred when exposed to 40×10^<-4> T under a constant J of 40 A/cm^2. The change in resistance of the sensor with the shock compaction method due to the measuring flux density B_<meas> do not exhibit a normal state for values of B_<ex> under 40×10^<-4> T and values of J less than 35 A/cm^2. Therefore, a magnetic measuring system can be constructed in order to realize a normal state of the sensor, and is biased for a homogeneous DC m
… More
agnetic flux density B_<bias> of 40×10^<-4> T.
B_<bias> is applied perpendicular to the surface of the magnetic sensor by use of a Helmholtz coil.
The magnetic sensitivity S scan be defined as
S=(100)/(B_<meas>・(R_<meas>(B_<meas>)-R_<meas>(B_<meas>=0T))/(R_<meas>(B_<meas>=0T)%/(10^<-4> T).
Here, R_<meas>(B_<meas>) and R_<meas>(B_<meas>=0 T) are the resistance in a measure magnetic field B_<meas>.
The magnetic sensitivity S of the specimen was approximately 13 %/(10^<-4> T) over the range of measurement of the magnetic field B_<meas> from 0 to±5×10^<-4> T, under a constant 40×10^<-4> T for the value of B_<ex>, being approximately 13 times greater than that of a giant magneto-resistance (GMR) sensor. It was, consequently, determined that it was possible to apply the bulk BPSCCO specimen as a highly sensitive magnetic sensor.
As one of the basic areas of research for the fabrication of a highly sensitive magnetic sensor, the present paper has examined a superconducting magnetic sensor, namely, that constructed from bulk BPSCCO, by use of the shock compaction method. From the all characteristics of the sensor constructed with the shock compaction method, it was found that the sensitivity S of the magnetic sensor was improved by the shock compaction method. These results were found to be important criteria for designing a highly sensitive magnetic sensor. Less
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Research Products
(14 results)
