The peculiarities of single-electron transport in granular Cr films

Miniature thin film granular structures had been fabricated by evaporation of chromium in oxygen atmosphere. The samples were 7-8-nm thick and 100-nm wide, while their length was 200, 500 and 1000 nm. The specific resistance of these samples measured at room temperature was varied from 15 to 35 kΩ per square. At temperatures below 200 mK, the current-voltage characteristics of the samples were hysteretic, exhibiting abrupt switching between the Coulomb blockade and a conducting state. The size of the current jump occurred near the blockade threshold was found to be from several pA up to about 1 nA.