Structure and electrical properties of the YBa_2Cu_3O_x thin films prepared with pulsed laser deposition in Ar/O_2 atmosphere

摘要

Superconducting YBa_2Cu_3O_x thin films were prepared with pulsed laser deposition in an Ar/O_2 mixture on NdGaO_3 (110) and LaAlO_3 (001) substrates. Structure and electrical properties of obtained films were studied as a function of the argon part in the gas mixture. The addition of argon suppresses formation of the non-superconducting oxides but enhances growth of the YBa_2Cu_3O_x grains with the a axis normal to the substrate plane. The further increase of argon partial pressure leads to a-oriented film formation with decrease of particle density on the film surface to less than 10~6 cm~(-2) and a rapid fall of the critical temperature due to insufficient oxygenation of the film.