Observation of dynamic flux-line relaxation in ion-irradiated Bi{sub 2}Sr{sub 1.8}CaCu{sub 2}O{sub {ital x}} by Lorentz microscopy

Journal Article · Mon Apr 01 00:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.9400· OSTI ID:280201

Harada, K; Kasai, H; Kamimura, O; Matsuda, T; Tonomura, A ^[1]; Okayasu, S; Kazumata, Y ^[2]

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1. Advanced Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-03 (Japan)
2. Japan Atomic Energy Research Institute, Tokai, Naka-gun, Ibaraki 319-11 (Japan)

The dynamical behavior of individual flux lines in Bi{sub 2}Sr{sub 1.8}CaCu{sub 2}O{sub {ital x}} thin film irradiated with 240-MeV Au{sup 14+} ions was investigated by Lorentz microscopy. To evaluate the pinning effect of columnar defects, the irradiation to a single crystal was partially blocked by using a mask. The flux-line relaxation after changing the equilibrium conditions in the two regions, one irradiated and the other without irradiation, was observed simultaneously. Just after switching off the magnetic field at 4.5 K, the flux-line density in both regions decayed logarithmically with time from uniform configuration. However, the relaxation rate in the irradiated region was less than that in the nonirradiated region. The flux-line density in the equilibrium state in the irradiated region was much higher than that in the nonirradiated region. These results revealed that the pinning force was enhanced by ion irradiation. Also it was observed that reversely polarized flux lines are generated and pair annihilation occurs between opposite flux lines during the relaxation, which has never been revealed by conventional macroscopic techniques. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 280201
• Journal Information: Physical Review, B: Condensed Matter, Vol. 53, Issue 14; Other Information: PBD: Apr 1996
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
HIGH-TC SUPERCONDUCTORS
MAGNETIC FLUX
IRRADIATION
CUPRATES
CALCIUM OXIDES
STRONTIUM OXIDES
BISMUTH OXIDES
TYPE-II SUPERCONDUCTORS
THIN FILMS
SUPERCONDUCTING FILMS
GOLD IONS
MONOCRYSTALS
RELAXATION TIME
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
ELECTRON MICROSCOPY
TRANSITION TEMPERATURE
PAIRING ENERGY
COOPER PAIRS
FLUX-LINE LATTICES