  The evolution of the structural and transport properties of underdoped
La$_{1.952}$Sr$_{0.048}$CuO$_4$ thin films under compressive epitaxial strain
has been studied. The films of different thicknesses $d$ (from 26 nm to 120 nm)
were deposited using an insulating target. The onset of superconductivity in
the films is observed at temperatures as high as 26 K, while small residual
resistance persists at low temperatures, indicating that superconductivity is
inhomogeneous. The resistance measured under perpendicular magnetic field
saturates below about 0.65 K, suggesting a possible existence of
nonconventional metallic state. The magnetic-field-tuned
superconductor-insulator transition is observed at magnetic field of about 32
T.

Superconductivity;Other Condensed Matter