Mössbauer and Magnetization study of polycrystalline multiferroic SmFeO3

The present work reports the preparation of polycrystalline SmFeO3 (SFO) and its characterization using bulk magnetization, 57Fe Mössbauer spectroscopy and ferroelectric polarization measurements. Temperature dependent bulk magnetization study shows crossover between zero-field cooled (ZFC) and field cooled (FC) curves at 4 K and slope variation of ZFC curve in 200-300 K region due to the spin switching transition which is found to be tunable with the applied magnetic field as observed in recent literature on single crystal SFO sample. From the temperature dependent Mössbauer measurements, transition from antiferromagnetic to paramagnetic state at about 708 K and signatures of temperature induced spin reorientation of Fe3+ are observed in quadrupole shift (QS) and A23 hyperfine parameters in the temperature range 450-500 K. The least square fitting to the temperature variation of Hint gives the critical exponent (β) ≈ 0.327 ± 0.001 suggesting the 3D Heisenberg magnet like behavior. The presence of ferroelectric ordering is shown from ferroelectric and PUND (Positive Up Negative Down) data measured at low temperatures (200 K).