Change in structural, ferroelectric, and magnetic properties of bismuth ferrite induced by doping with gadolinium

Bismuth ferrite, BiFeO3, was doped with a wide range of concentrations (0-30%) of Gd in order to investigate structural, ferroelectric, and magnetic properties and their correlation. Powder samples of Bi1-xGdxFeO3 (x = 0.00-0.30) were prepared using the hydro-evaporation synthesis method. Sintering process at 870 degrees C for 6 h of as-prepared, Gd doped BiFeO3 powders resulted in ceramic samples with relative densities in the range of (74-86) %. XRD analysis revealed that Bi1-xGdxFeO3 samples (x = 0.00-0.09) crystallized in rhombohedral phase; Bi1-xGdxFeO3 samples (x = 0.10-0.20) contained both rhombohedral and orthorhombic phases, while Bi1-xGdxFeO3 (x = 0.30) sample contained only the orthorhombic phase. The structural parameters obtained after Rietveld refinement for single-phase Bi1-xGdxFeO3 ceramic samples and microstructure image analysis were correlated with the results of ferroelectric and magnetic measurements. Bi1-xGdxFeO3 (x = 0.0625, 0.075, 0.09) samples showed improved ferroelectric properties and reduced leakage current density in comparison with undoped BiFeO3. Gradual increase in Gd content in BiFeO3 led to enhanced magnetic responses and weak ferromagnetic behavior.