Speaker
Mr
Mohammad Jahangir Hossain
(The School of Materials Science and Engineering, UNSW Australia)
Description
The solid solution system Bi1/2Na1/2TiO3 – xBaTiO3 (BNT-BT) has attracted wide research interest in the scientific community as a potential high-strain lead-free piezoelectric material. The electro-mechanical coupling mechanisms in a series of BNT-BT solid solutions with the BT content ranging from 5 mol% to 8 mol% in 0.25 mol% steps have been studied using in situ high-energy synchrotron x-ray diffraction (XRD). Unipolar stress cycling with a maximum stress ~600 MPa, and bipolar electric-field cycling with maximum field of 5 kV/mm were applied in two separate experiments. In the initial state, the BNT-xBT series exhibited a region of pseudo-cubic symmetry between x~5-8. During application of both stress and electric field, lower BT content samples (x < 5.25) tended to transform to rhombohedral symmetry, while higher BT content (x > 7.75) tended to go tetragonal. Compositions between these tended to transform to mixed phase symmetry. The results show that the stress and electric-field-induced phase transformation mechanisms are highly analogous in this material system within the range studied here.
Keywords: Piezoelectricity, Diffraction, Strain, Ferroelectric
Primary author
Mr
Mohammad Jahangir Hossain
(The School of Materials Science and Engineering, UNSW Australia)
Co-authors
John Daniels
(UNSW)
Mr
Neamul Khansur
(UNSW)
Mr
Patrick Tung
(University of New South Wales)
Dr
Zhiyang Wang
(UNSW Australia)
