Normal State Transport Parameters of Epitaxial Thin Films of YBa sub 2 Cu sub 3 O sub (7-delta).

We report on a striking transport phenomenon in very high quality (j sub c ~3.4x10 sup 6 A/cm sup 2 at T=77K) epitaxial thin films of high-T sub c Y-Ba-Cu-O in the normal state. With increasing superconducting performance, as characterized by the transition temperature, transition temperature width, and critical current density, the resistivity rho, as well as the Hall coefficient R sub H , both assume remarkably simple temperature dependences rho = alpha T and R sub H sup (-1) = beta T leading to a Hall mobility mu sub H proportional to T sup (-2). The magnetoresistance at 10T is less than |Delta rho/rho|100 sup (-3). We discuss an extreme two-carrier model to asses the T-dependence of R sub H .