Ap. Brodyanskii et al., OBSERVATION OF A NONOHMIC COMPONENT OF SP ONTANEOUS CONDUCTIVITY FLUCTUATIONS IN YBA2CU3O7-X THIN-FILMS, Fizika nizkih temperatur, 20(9), 1994, pp. 974-977
Resistive and noise properties of thin single-crystal YBa2Cu3O7-x film
s with the c axis being parallel to the substrate plane have been stud
ied. In the normal state as well as in the region of the superconducti
ng transition we observed variations of the resistance fluctuation spe
ctral density with current, which is direct evidence of structure elem
ents with nonlinear current-voltage relationships present in high-T(c)
materials. On the basis of a comparison of data for c(parallel-to)- a
nd c(perpendicular-to) - films, certain inferences are made about the
microscopic origin of the structure elements, responsible for the curr
ent nonlinearities in the noise properties of HTSC.