Improved Quality Of Niobium Josephson Junctions Due To Reduced Barrier Interface Reactions
Original Publication Date: 1979-Dec-01
Included in the Prior Art Database: 2005-Feb-20
When making Nb Josephson devices it is important to avoid any interaction of the electrodes with material which degrades superconductivity. Oxygen, e.g., is well known to dissolve in the metallic Nb, thereby lowering the critical temperature T(c). It also forms various kinds of oxides out of which NbO is a normal conductor. It increases excess current of Josephson junctions if present as a thin layer at the barrier interface.