We investigated the crystal structure, physical properties and ferroelectric performance of bulk material obtained by mixing and sintering Bi 3 . 2 5 La 0 . 7 5 Ti 3 O 1 2 and Bi 4 Si 3 O 1 2 or Bi 2 SiO 5 for use as a novel ferroelectric material for ferroelectric memory. The resulting material was identified as a structure whereby, all of the peaks, as determined by powder X-ray and neutron diffraction, were the same as Bi 3 . 2 5 La 0 . 7 5 Ti 3 O 1 2 , and thus a single phase was obtained. Moreover, we investigated the crystal structure of the material by neutron diffraction, and the obtained results suggested that Si is substituted on Ti sites. The resulting material was investigated by SEM, and grains grown relative to Bi 3 . 2 5 La 0 . 7 5 Ti 3 O 1 2 were observed. Based on P-E hysteresis measurements, this sample has a high remanent polarization (P r ) and a low coercive field (E c ) relative to Bi 3 . 2 5 La 0 . 7 5 Ti 3 O 1 2 , as well as improved overall ferroelectric characteristics.