Abstract
We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.
| Original language | English |
|---|---|
| Pages (from-to) | 353-356 |
| Number of pages | 4 |
| Journal | Physica C: Superconductivity and its applications |
| Volume | 437-438 |
| Issue number | SPEC. ISS. |
| DOIs | |
| Publication status | Published - 2006 May 15 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
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Vortex dynamics in spacing-graded array of defects on a niobium film. / Wu, T. C.; Horng, Lance; Wu, J. C.; Hsiao, C. W.; Kolacek, Jan; Yang, T. J.
In: Physica C: Superconductivity and its applications, Vol. 437-438, No. SPEC. ISS., 15.05.2006, p. 353-356.Research output: Contribution to journal › Article
TY - JOUR
T1 - Vortex dynamics in spacing-graded array of defects on a niobium film
AU - Wu, T. C.
AU - Horng, Lance
AU - Wu, J. C.
AU - Hsiao, C. W.
AU - Kolacek, Jan
AU - Yang, T. J.
PY - 2006/5/15
Y1 - 2006/5/15
N2 - We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.
AB - We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.
UR - http://www.scopus.com/inward/record.url?scp=33745464092&partnerID=8YFLogxK
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U2 - 10.1016/j.physc.2005.12.047
DO - 10.1016/j.physc.2005.12.047
M3 - Article
AN - SCOPUS:33745464092
VL - 437-438
SP - 353
EP - 356
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - SPEC. ISS.
ER -