Study of room temperature ferromagnetic and ferroelectric properties in α-Fe_1.6Ga_0.4O₃ alloy

The compound α-Fe_1.6Ga_0.4O₃ has been prepared by mechanical alloying and subsequent vacuum annealing at 800 °C. X-ray diffraction and Raman spectroscopy confirmed rhombohedral phase. The samples have shown enhanced ferromagnetic properties in comparison with α-Fe₂O₃ sample. The samples also exhibited good signature of ferroelectric polarization. Increase of alloying time has affected the variation of ferromagnetic and ferroelectric parameters. The samples with 50 h alloying time showed relatively large leakage of polarization, where as the samples at lower and higher alloying time showed better ferroelectric properties. Details of the ferroelectric loop have been studied at different applied voltages and frequencies. It has been found that leakage of polarization can be optimized by adjusting the frequency of the applied voltage. The ferroelectric properties have been understood by correlating the observations of the dielectric properties (dielectric loss, dielectric constant, and electrical conductivity) of the samples. The results are interesting for understanding the mechanism of ferroelectric properties in non-traditional ferroelectrics. This work opens a wide scope for reviewing the ferroelectric and multiferroic properties in metal doped hematite system, which is structurally different from orthorhombic phase of GaFeO₃ that showed ferroelectric properties. - Highlights: • Mechanical alloying and vacuum annealing used to form α-Fe_1.6Ga_0.4O₃. • The samples have been characterized using XRD, SEM-EDX, and Raman spectroscopy. • Ferromagnetism and ferroelectric properties have been studied at room temperature. • Structural disorder, spin canting and spin–lattice coupling have been identified as the origin of ferroelectric properties. • The results are important to understand non-traditional ferromagnetic and ferroelectrics