Preparation of Oxygen Ion Conducting Doped Lanthanum Gallate Thin Films on Amorphous and Single Crystal Substrates by Pulsed Laser Deposition

摘要

An La_(1-x)Sr_xGa_(1-y-x)Mg_yCo_zO_(3-(x+y+z)/2) (LSGMCO) has attracted much attention because it can be useable as an electrolyte of a solid oxide fuel cell due to its high oxide ion conductivity. We prepared LSGMCO thin films on silica glass and LaAlO_3 single crystal substrates by pulsed laser deposition and evaluated their properties. LSGMCO thin films deposited at 800℃ were poly-crystal and the deposition pressure affected their surface morphologies. In the case of the LaAlO_3 single crystal substrate, a c-axis oriented LSGMCO thin film was obtained. DC conductivity and complex impedance of LSGMCO thin films were measured in vacuum atmosphere to investigate the effect of the crystal orientation on the oxide ion conductivity. It was revealed that resistance at a grain boundary of films is more dominant compare with the grain interior.