DIMENSIONAL CROSSOVER FOR INTRINSIC DEJOSEPHSON EFFECT IN BI2SR2CACU2O8 2212 SINGLE-CRYSTAL WHISKERS

The variations of the critical current I-c across the layers as a func tion of the parallel magnetic field H have been studied on small area stacked junctions fabricated from perfect single crystal Bi2Sr2CaCu2O8 whiskers. Intrinsic de Josephson effect has been clearly demonstrated on structures with in-plane size L less than 20 mu m. With L increase s, a dimensional crossover to monotonic size independent behavior of I -c(H) has been observed. I-c(H) decrease in this region is proportiona l to root H in accordance with the Fistul-Giuliani theory.