Size effects in electrical behavior of high-T/sub c/ thin-film bridges

The size effects in electrical characteristics of polycrystalline YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin-film bridges were studied in the temperature range 4-300 K. It is shown that at T>T/sub c/ the decrease of bridge widths w from 200 to 10 mu m leads to an increase of resistance R/sub Square Operator / of several times and to a change in R/sub Square Operator / (T) behavior from a metallic type to an activation type. At T