1/f noise in Tl2Ba2Ca1Cu2O8 thin films: Influence of crystal structure

Abstract

1/f noise measurements performed on Tl2Ba2Ca1Cu2O8 thin films show that the amplitude of the noise spectral density (Sv/V2) in the normal state may be comparable with that in conventional metals, in contrast with the much larger Sv/V2 observed in other copper oxide materials. In the superconducting transition region the 1/f noise is greatly reduced in some films that are highly aligned along the c axis.

On the anomalous flicker noise intensity in high-temperature superconductors

“…The authors [14,15] attribute this noise reduction to the higher quality of their samples. Earlier, similar reduction was observed [16] in thin films of Tl 2 Ba 2 Ca 2 Cu 2 O 8 .…”

“…Soon after the work [11], considerably lower values of α (close to those in conventional metals) were detected [16] in thin films of Tl 2 Ba 2 Ca 2 Cu 2 O 8 . The films had a = 1 µm, and γ was loosely indicated to be in the range 1.10 ± 0.15 for all temperatures.…”

A Search for a Low Anisotropic Superconductor

“…The highest critical current density in double layer TlO compounds is attained in Tl-2223 thin films, which is of the order of 107 A/cm 2 (90K, 0T) [5]. On the other hand the critical current density of Tl-2212 superconductor is in the range of 10 5 -10 6 A/cm 2 at 77K depending upon the deposition techniques used [42][43][44][45][46].…”

Measurements and analysis of the noise spectral density of YBCO films

“…The measurement of noise in High T c Superconductors (HTSC's) is one of the most valuable tools in the study of disorder and dynamics of vortices in such materials [1]. In HTSC's, both magnetic flux [2] and voltage noise [3][4][5][6][7] have been examined mainly in the regime near the zero magnetic field. The results have quite naturally been interpreted in terms of thermal activation over barriers and microscopic defects, or by the use of percolation model.…”