Upward curvature of the perpendicular resistive critical magnetic field in the highly layered superconductor (LaSe)1.14(NbSe2)2

The misfit layer compound (LaSe)1.14(NbSe2)2 undergoes a superconducting transition at 5.43 K. The anisotropy of this compound calculated by the angular dependence of the critical field at 4.2 K is 35 and its perpendicular resistive critical magnetic field, H⊥ *, taken at a fraction of the normal state resistance, rises steeply when the temperature is reduced with an upward curvature and does not show any sign of saturation down to 0.050 K. This anomalous behaviour is probably induced by important thermal fluctuations.