Domain switching of barium titanate ceramics induced by surface grinding

摘要

As-sintered and subsequently ground barium titanate ceramics have been examined by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and their relative permittivity determined. A compressive residual stress of similar to316 MPa parallel to the surface is found in the near surface region of the ground samples. A ferroelectric domain texture with the polar axis normal to the sample surface is developed due to the compressive residual stress. A depth gradient of this texture is observed by varying the penetration depth of the X-ray beam through sample tilting. Because the stressed zone is only confined to the near surface region, no significant difference in relative permittivity is observed between the as-sintered and the ground samples. Comparing with the as-sintered samples, considerable diffuseness in tetragonal to cubic phase transition is observed from the ground samples by XRD during heating. This implies that internal stresses can also cause diffuse phase transition. (C) 2004 Elsevier B.V. All rights reserved.