Ceramics-Silikáty 57 (1) 22-27 (2013)

PHASE AND MORPHOLOGY FORMATION OF Na DOPED PMN THIN FILMS PREPARED BY MODIFIED SOL-GEL METHOD

Na doped lead magnesium niobate Pb(Mg_1/3Nb_2/3)O₃ (Na-PMN) thin films of 100 nm thickness were prepared by modified sol-gel route with niobium precursor. Na-PMN films were deposited from sol derived using tartaric acid modified polymerizable complex method by mixing of Nb-tartarate (Pechini) complex with Na, Pb and Mg acetates at 80°C with molar ratio of Na : Pb : Mg : Nb = 1/2 : 1 :1/3 : 2/3 on Pt/Al₂O₃ substrates by spin-coating method. In Na doped PMN film the perovskite Pb(Mg_1/3Nb_2/3)O₃ phase (65 vol. %) and a small amount of pyrochlore Na₂Nb₈O₂₁ phase were revealed after sintering at 650°C. In the microstructure of 2-layered Na-PMN/Pt/Al₂O₃ thin film, with ~9.5 nm of roughness, the bimodal particle distribution was observed with small spherical particles of pyrochlore phase and larger sponge-like particles of the perovskite phase. The smallest visible spherical particles (~30 nm) and mutually interconected particles (~125 nm) were found in TEM and AFM micrographs.

Keywords: Sol-gel, PMN thin films, Pyrochlore, Perovskite phase