Fabrication and characterization of (Ba, Sr)RuO3 ceramic targets and thin films for ferroelectric BaTiO3 thin-film capacitors

Abstract

We report the preparation of (Ba, Sr)RuO3 ceramic targets in a conventional process in air at ambient pressure and their epitaxial thin-film growth on Ba0.7Sr0.3TiO3 buffered SrTiO3 substrates. We found that a simultaneous addition of CuO and SiO2 is effective in obtaining the relatively dense ceramics. The microstructural and chemical investigations show that the synergetic effect of a liquid-phase (Ba-Sr-O) assisted grain growth accelerated by Cu-derived Ru charge inhomogeneity along with a rearrangement of grains promoted by a liquid-phase silicate is the mechanism of the (Ba, Sr)RuO3 densification. We demonstrate that all epitaxial BaTiO3 thin-film capacitors with (Ba1-xSrx)RuO3 electrodes can be obtained up to x of 0.6.