We report on low-temperature scanning tunneling microscopy/spectroscopy experiments performed on superconducting boron-doped nanocrystalline diamond (NCD) thin films prepared by chemical-vapor deposition methods. The most representative sample reveals the observed superconducting gap (Δ) highly modulated over a length scale on the order of ∼30nm, which is much shorter than the typical diamond grain size. The sample local and macroscopic behavior favors for the Δ modulation as being an intrinsic property of the NCD granules. On the other hand, Δ shows its temperature dependence [Δ (T)] consistent with the results obtained by Fominov and Feigel'man [Phys. Rev. B 63, 094518 (2001)], who studied theoretically the behavior of the superconducting gap of a BCS superconductor in contact with a normal layer by solving the one-dimensional Usadel equations on the superconducting side of the superconducting to normal interface. © 2009 The American Physical Society.
|Original language||American English|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 21 Dec 2009|
Willems, B. L., Dao-, V. H., Vanacken, J., Chibotaru, L. F., Moshchalkov, V. V., Guillamón, I., Suderow, H., Vieira, S., Janssens, S. D., Williams, O. A., Haenen, K., & Wagner, P. (2009). Intrinsic granularity in nanocrystalline boron-doped diamond films measured by scanning tunneling microscopy. Physical Review B - Condensed Matter and Materials Physics. https://doi.org/10.1103/PhysRevB.80.224518