TY - JOUR
T1 - A simple measurement technique for critical current density by using a permanent magnet
AU - Ohshima, S.
AU - Takeishi, K.
AU - Saito, A.
AU - Mukaida, M.
AU - Takano, Y.
AU - Nakamura, T.
AU - Suzuki, T.
AU - Yokoo, M.
N1 - Funding Information:
Manuscript received October 4, 2004. This work was supported in part by CREST of Japan Science and Technology Corporation, Yamagata Prefecture, Marubun Research Promotion Foundation, the Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aid for Young Scientists (B), 16760019, 2004. A part of this work was carried out in the clean room of Yamagata University.
PY - 2005/6
Y1 - 2005/6
N2 - We developed a novel nondestructive and contactless method for measurements of critical current density (Jc) in high-temperature superconductor (HTS) thin films by using a permanent magnet (Sm2Co17). This measurement technique is based on a repulsive force (Fr) and attractive force (Fa) between the magnet and HTS film caused by the shielding currents and pinning forces. The Fr and Fa were measured by using a high-resolution load sensor changing the distance (L) between the magnet and HTS film. An effective maximum repulsive force (F m,eff) could be determined from an extrapolated value of the F r vs. L curve for L = 0 mm. We investigated the relationship of the Jc to theFm,eff in many HTS (YBa2Cu 3O7-δ and ErBa2Cu3O 7-δ) samples. The standard Jc of HTS films was measured by using an inductive measurement system produced from THEVA GmbH. We found that the Jc is almost proportional to the two-thirds power of the Fm,eff normalized by the film thickness. This result indicates that the simple permanent magnet technique can be easily estimate the J c of the HTS films. This system has good reproducibility for the Jc measurements and is useful to provide a rapid, routine characterization of the superconductivity in the HTS materials.
AB - We developed a novel nondestructive and contactless method for measurements of critical current density (Jc) in high-temperature superconductor (HTS) thin films by using a permanent magnet (Sm2Co17). This measurement technique is based on a repulsive force (Fr) and attractive force (Fa) between the magnet and HTS film caused by the shielding currents and pinning forces. The Fr and Fa were measured by using a high-resolution load sensor changing the distance (L) between the magnet and HTS film. An effective maximum repulsive force (F m,eff) could be determined from an extrapolated value of the F r vs. L curve for L = 0 mm. We investigated the relationship of the Jc to theFm,eff in many HTS (YBa2Cu 3O7-δ and ErBa2Cu3O 7-δ) samples. The standard Jc of HTS films was measured by using an inductive measurement system produced from THEVA GmbH. We found that the Jc is almost proportional to the two-thirds power of the Fm,eff normalized by the film thickness. This result indicates that the simple permanent magnet technique can be easily estimate the J c of the HTS films. This system has good reproducibility for the Jc measurements and is useful to provide a rapid, routine characterization of the superconductivity in the HTS materials.
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U2 - 10.1109/TASC.2005.848631
DO - 10.1109/TASC.2005.848631
M3 - Article
AN - SCOPUS:22144477164
SN - 1051-8223
VL - 15
SP - 2911
EP - 2914
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 2 PART III
ER -