Structural, Optical, and Magnetic Properties of o-TbFeO3 Nanomaterials Synthesized by the co-Precipitation Method

Following the co-precipitation method for producing terbium orthoferrite (TbFeO3), the final products were denoted as TbFeO3-650, -750, and -850. A single-phase of orthorhombic TbFeO3 crystals (o-TbFeO3) was obtained with a calcination temperature of up to 850 degrees C, while in the range of 650-750 degrees C there was still a small amount of terbium and iron oxide phases. The average size of o-TbFeO3 crystallites for the TbFeO3-850 sample was about 76 nm and was larger than that of TbFeO3-650 (similar to 45 nm) and TbFeO3-750 (similar to 47 nm). The o-TbFeO3 crystal structure in all samples was found to be distorted. In the applied field from -15 to +15 kOe, all of the samples had low values of coercive field (5-11 center dot 10(-3) Oe) but high values of net magnetization (2.06-2.40 emu center dot g(-1)); the samples appeared to behave as paramagnetic materials. It was shown that the TbFeO3-850 sample has slightly better magnetic properties than the two others. An average grain size of about 79 nm was found in the TbFeO3-850 sample, which exhibited a morphology of sphere-like shapes with highly agglomerated grains. The TbFeO3-850 sample demonstrated a high absorbance at wavelengths of 400-600 nm, with a direct bandgap of about 2.68 eV.