Influence of in-situ magnetic field pressing on the structural and multiferroic behaviour of BiFeO3 ceramics

Polycrystalline single phase BiFeO3 (BFO) ceramic samples have been prepared by conventional solid state sintering and also by in-situ magnetic field pressing followed by solid state sintering. The influence of in-situ magnetic field pressing on the structural, magnetic, ferroelectric and thermal properties has been investigated in this work. X-ray diffraction analysis and Reitveld refinement shows the single phase characteristics of BFO samples. Further texture formation and the development of compressive lattice strain have been observed in the magnetic field pressed samples. A change in Fe–O–Fe bond angle and suppression of spiral spin structure results in the enhanced magnetization value Ms = 136 memu/g at 2 T. Similarly spontaneous polarization has also improved with a Pmax value of 1.3 μC/cm2. DSC plot shows a significant variation in heat flow and enthalpy at the Neel transition (TN = 372 °C) and ferro to paraelectric transition (TC = 820 °C) for the magnetic field pressed BFO samples.