Chemical synthesis and crystal structure of the Aurivillius phase Bi4Ti3O12

Molten salt (MS) and sol-gel (SG) synthesis of Aurivillius ceramics, with formula Bi4Ti3O12, is investigated. The implementation of these methods leads to the formation of the considered phase, with fake morphology in FS method and spherical particles in SG. Rietveld diffractometric structural refinement is performed. The structure is monoclinic, space group A1n1. The obtained lattice parameters are the following: a = 5.4458 (2) Angstrom, b = 5.4075 (2) Angstrom, c = 32.800 (2) Angstrom, beta = 89.963 (3)degrees. The detection of monoclinic symmetry is consistent with recent fndings that the spontaneous electric dipole does not point towards crystallographic axis a, but also shows a certain component along axis c.