TRANSPORT PROPERTIES OF ELECTRON-DOPED La_2−xCe_xCuO₄ THIN FILM IN THE UNDER-DOPED REGION

Underdoped electron-doped La 2-x Ce x CuO 4 ( x =0.06-0.09) thin films were successfully grown and investigated for the transport properties in ab-plane. It was found that the in-plane resistivity ρab shows a semiconductor behavior when x =0.06, with increasing the Ce concentration to the optimal doping level, it changes to the two dimensional Fermi-liquid behavior. In the films with x≥0.08, a Kondo effect like scattering is observed in the low temperature range.