Abstract
The ability to control the tilt angle of CuO2 planes with respect to the film surface has led to successful synthesis of single-domain, epitaxial La2-xSrxCuO4 films of (103) and (109) orientations corresponding to tilt angles of 21°and 49°, respectively. The systematics of the c-axis resistivity and transport anisotropy ρc/ρab have been studied as a function of Sr doping varying from 0.04 to 0.34 over 2≤T≤800 K. The temperature dependence of the c-axis resistivity evolves from semiconductinglike behavior in the lightly doped and optimally (superconducting) doped regions (x≤0.15) to metallic behavior in the heavily doped region (x0.25), displaying a notable discontinuity of the slope at the tetragonal-orthorhombic phase transformation. The crossover from two-dimensional metallic transport to strongly anisotropic three-dimensional metallic transport was observed near the superconducting phase boundary (x∼0.22). The evolution of transport anisotropy ρc/ρab closely resembles the evolution of the electronic orbital character of doping-induced holes, hence suggesting a connection between the two-dimensional electronic structure and superconductivity. © 1993 The American Physical Society.