X-ray absorption spectroscopy identification of Mn-doped Bi 3.25La0.75Ti3O12 ceramics

Abstract

In this work, x-ray absorption spectroscopy was performed to characterize Mn-doped Bi3.25La0.75Ti3O12(BLT) ceramics with various MnO2dopants. The x-ray absorption near-edge structure (XANES) was analyzed in combination with first principle calculation of Mn K-edge to identify atomic position of Mn in BLT. The result confirms Mn4+substituting on Ti4+-site in BLT. Further, the extended x-ray absorption fine structure (EXAFS) was examined where Mn K-edge of Mn-doped BLT was compared to that of Ti K-edge of BLT in R-space. The result shows radial distances between Mn4+and O2-ions in ab-axis are almost equal and decrease with increasing Mn-doping contents. This is strong evidence that Mn4+substituting on Ti4+site can be reduced the orthorhombicity, which increase the polarization domains size and enhance remnant polarization, speed up the polarization domains movement and lessen coercive field. © 2013 Copyright Taylor and Francis Group, LLC.