Anisotropic electrical transport property in La4BaCu5O13+delta and La4BaCu4NiO13+delta epitaxial thin films

Epitaxial films of La4BaCu5O13+delta and La4BaCu4NiO13+delta oxides are gro wn with a-b plane parallel to (100) of LaAlO3 and SrTiO3 by pulsed-laser de position. The conductivity measurements performed along the c direction usi ng LaNiO3 as the electrode show metallic behavior whereas they show semicon ducting behavior in the a-b plane. Anisotropic transport property of these thin films is explained on the basis of nearly 180 degrees connected Cu-O-C u chains with an average Cu-O distance of 1.94 Angstrom along the c directi on and nearly 180 degrees and 90 degrees connected Cu-O-Cu chains in the a- b plane with short and long Cu-O distances ranging from 1.863 to 2.303 Angs trom. YBa2Cu3O7-x has been grown along (00l) on La4BaCu5O13+delta and shows a T-c of 88 K. (C) 1999 American Institute of Physics. [S0003-6951(99)0493 7-2].