Geometrical resonances have been observed in the electron tunneling characteristics of rf sputtered niobium films. The data scale correctly with film thickness and result in a mean fermi velocity in fair agreement with other measurements. © 1971.
Smith, C. W., & Miller, N. C. (1971). Geometrical resonance effect in sputtered superconducting niobium. Physics Letters A, 34(3), 147–148. https://doi.org/10.1016/0375-9601(71)90797-3