Thickness-tuned Superconductor-to-Insulator Transitions under magnetic   field in a-NbSi
  We have studied the thickness-induced superconductor-to-insulator transition in the presence of a magnetic field for a-NbSi thin films. Analyzing the critical behavior of this system within the "dirty boson model", we have found a critical exponents product of $\nu_d z$ > 0.4. The corresponding phase diagram in the (H,d) plane is inferred. This small exponent product as well as the non-universal value of the critical resistance found at the transition call for further investigations in order to thoroughly understand these transitions. 
C.A. Marrache-Kikuchi, H. Aubin, A. Pourret, K. Behnia, J. Lesueur, L.   Berge, L. Dumoulin