Ferroelectric characteristics of silicate-bound Bi4Ti3O12 thin films

40-nm-thick Bi4Ti3O12 films have been deposited by spin coating with a hybrid precursor solution of bismuth-2-ethylhexanoate, titanium tetraisopropoxide and tetraethysilicate. The 500 °C-annealed thin film consists of Bi4Ti3O12 grains bound by ultra-thin amorphous silicate layers. The film shows a high degree of crystallinity with random orientation and exhibits a structure-dependent propeller-like P–V hysteresis loop. The ultra-thin layer of amorphous silicate is found to have multiple functions of binder, compositional buffer and insulator, which results in an improvement of the electrical properties of the Bi4Ti3O12-Bi2O3×SiO2 thin films.