Synthesis and colloidal dispersion of nanocrystalline ferroelectric Nd-substituted Bi4Ti3O12 powder by mechanical alloying

Crystalline Nd-substituted Bi4Ti3O12 (BNT) nanopowder was directly produced from a stoichiometric oxide mixture by intense milling. During the milling, mechanical alloying between the constituent oxides occurred, resulting in a sequential phase transformation from metastable fluorite to BNT with increasing milling time. The formation of the BNT phase was complete after 9 h of milling. The resulting powder consisted of nearly monodisperse crystallites of ∼18 nm average size, exhibiting a zeta potential of +50 mV at pH ∼ 2.