Structure and physical properties of (Zn, Ti) co-doped BiFeO3 ceramics prepared using three different processes

Abstract

In this paper, BiFe1–2×ZnxTixO3 (BFZTO) (where x = 0, 0.02, and 0.03) ceramics were prepared using three different processes and resulting samples were evaluated using various characterization techniques. X-ray diffraction (XRD) patterns indicate that all BFZTO samples exhibit typical diffraction pattern of R3c space group. Results further show that the combination of cold isostatic pressing and conventional sintering (CIP-CS) is an effective method for preparing high-performance BiFeO3 (BFO) ceramics. BFZTO (x = 0.02) samples prepared using CIP-CS method possess large remnant polarization of 1.18 μC/cm2 and coercive field of 11.5 kV/cm. Meanwhile, the same sample displays enhanced dielectric properties due to the formation of defect complexes and increase in grain boundaries, which reduce the amount of free charge and restrict the transportation of charged defects and reversal of domain. For CIP-CS BFZTO ceramics, UV–visible diffuse absorption spectra show that the value of optical band gap lies within the range of 1.72–1.98 eV, which indicates potential applications of the ceramic in photocatalyst and photoconductive devices.