Superconducting tunneling study of vanadium

The tunneling spectroscopy of McMillan and Rowell is extended to vanadium, with the use of clean and highly ordered structures of the form M- Al2O3-Al/V. The Eliashberg function α2F(E) is determined and leads to λ=0.82±0.05 and μph*=0.15±0.03. These tunneling results, the first available for V, indicate a smaller influence of paramagnon spin fluctuations in suppressing superconductivity in vanadium than recently suggested, but do not rule out such effects at a level λs∼0.1.