Josephson plasma observed in underdoped (110) YBa2Cu3O7-delta films

(110) oriented YBa2Cu3O7-delta thin films have been epitaxially grown on vi cinal (110)SrTiO3 substrates by pulsed-laser deposition. Films with differe nt oxygen deficiencies were obtained by annealing under various oxygen ambi ent. These films have very smooth surface and with their c axis aligned in one direction in the substrate plane. Electronic transport and polarized fa r-infrared reflectivity measurements reveal the unique features of the c-ax is charge dynamics. A c-axis far-infrared reflectivity edge associated with the Josephson plasma in the superconducting state is observed. Our results demonstrate the potential usage of (110) thin films for the investigation of intrinsic interlayer charge dynamics as well as device application of hi gh T-c superconductors. (C) 2001 American Institute of Physics.