Spark plasma sintering of hydrothermally synthesized bismuth ferrite

Bismuth ferrite, BiFeO3 (BFO), powder was synthesized by ydrothermal method from Bi(NO3)3·5 H2O and Fe(NO3)3·9 H2O as precursors. The synthesized powder was further sintered using spark plasma sintering (SPS). The sintering conditions were optimized in order to achieve high density, minimal amount of secondary phases and improved ferroelectric and magnetic properties. The optimal structure and properties were achieved after spark plasma sintering at 630 °C for 20 min, under uniaxial pressure of 90 MPa. The composition, microstructure, ferroelectric and magnetic properties of the SPS samples were characterized and compared to those of conventionally sintered ceramics obtained from the same powder. Although the samples sintered using conventional method showed slightly lower amount of secondary phases, the spark plasma sintered samples exhibited favourable microstructure and better ferroelectric properties.