Quick growth optimization of complex oxide, Y-type magnetoplumbite (Ba2Co2Fe12O22 (Co2Y)) thin films is demonstrated by using combinatorial thin film technology. Planning a Coo buffer layer on MgAl2O4(1 1 1) substrate was found to be very effective for preventing the phase separation of Co deficient impurity (BaFe2O4) and forming the desired Co2Y phase. The combinatorial pulsed laser deposition and subsequent concurrent X-ray diffraction facilitate the production of Y-type magnetoplumbite thin film in a single phase. (C) 2002 Elsevier Science B.V All rights reserved.