Title :
Measurements of transport properties and noise power spectral densities for Bi/sub 2/Sr/sub 2/Ca/sub 1/Cu/sub 2/O/sub x/ single crystals
Author :
Han, K.H. ; Joo, M.K. ; Shin, H.J. ; Lee, S.-I. ; Salk, S.-H.S.
Author_Institution :
Dept. of Phys., Pohang Inst. of Sci. & Technol., Kyung-Buk, South Korea
fDate :
3/1/1993 12:00:00 AM
Abstract :
The authors measured the current-voltage characteristics of Bi/sub 2/Sr/sub 2/Ca/sub 1/Cu/sub 2/O/sub x/ single crystals along the a-b plane and observed the behavior of the Kosterlitz-Thouless (K-T) transition. The noise power spectral density, S/sub v/(f), near the K-T transition temperature was studied in detail by changing the temperature, magnetic field, and current S/sub v/(f) at temperatures above the K-T transition temperature T/sub KT/ shows a 1/f behavior, regardless of the external magnetic field. However, near T/sub KT/, the S/sub v/(f) deviates markedly from the 1/f behavior for the experimental frequency range. It is believed that the anomalous variation of frequency dependence near T/sub KT/ originates from the fluctuation effect of the vortex-antivortex pairs, i.e., their annihilation-creating fluctuations.<>
Keywords :
bismuth compounds; calcium compounds; fluctuations in superconductors; flux pinning; high-temperature superconductors; random noise; strontium compounds; 1/f behavior; Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ single crystals; HTSC; Kosterlitz-Thouless transition; annihilation-creating fluctuations; anomalous variation; current-voltage characteristics; fluctuation effect; frequency dependence; noise power spectral densities; transport properties; vortex-antivortex pairs; Bismuth; Crystals; Current measurement; Current-voltage characteristics; Fluctuations; Magnetic fields; Noise measurement; Power measurement; Strontium; Temperature;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
