Aurivillius phase materials are ferroelectrics in which the polarization is predominantly along the a-axis, in-plane direction. We employed lateral piezoresponse force microscopy (PFM) to confirm in-plane piezoelectricity for samples with three different compositions: However, the vertical piezoresponse decreased to 3.6 pm/V for Bi6Ti2.50Fe1.77Mn0.73O18 (50% Ti at B-site, Fig. ). Furthermore, hysteresis shape is not concave for the Bi6Ti2.50Fe1.77Mn0.73O18