Structural characterization and superconductivity in the misfit layer compound (LaSe)1.14(NbSe2)

The crystal structure of the new misfit layer compound (LaSe)1.14(NbSe2) has been determined; it corresponds to an alternating of one |LaSe| layer and one |NbSe2| slab stacked along their c direction with a mismatch along the a direction: a|LaSe|/a|NbSe2| approaching √3. This compound undergoes a superconducting transition at 1.32 K. The superconducting resistive transitions versus magnetic field when the field is oriented perpendicular to the layer structure broaden and shift to high field when the temperature is reduced and the resistive critical field H⊥*(T) taken at a fraction of the normal state resistance shows an upward curvature and increases steeply without any sign of saturation down to 0.035 K.