Physicochemical properties of terbium orthoferrite nanoparticles synthesized by simple co-precipitation method using ethanol

TbFeO 3 nanoparticles were successfully synthesized via an ethanol-mediated co-precipitation method using ammonia as the precipitating agent, followed by calcination at 750–950 °C. Phase-pure orthorhombic TbFeO 3 was obtained for all calcination temperatures, as confirmed by the characteristic PXRD diffraction peaks and FT-IR vibration bands. Increasing calcination temperature improved crystallinity and increased crystallite size from ∼43 to ∼66 nm, while lattice parameters remained nearly constant. TEM images revealed agglomerated nearly spherical nanoparticles with an average particle size of ∼48 nm. All samples exhibited strong visible-light absorption with a decrease in band gap from 2.44 to 2.40 eV as the calcination temperature increased. Magnetic measurements revealed nearly linear hysteresis loops with low coercivities (∼0.02 Oe), low remanent magnetizations (2.53–3.07 × 10 −6 emu g −1 ), and saturation magnetizations of 2.11–2.38 emu g −1 , consistent with dominant paramagnetic contributions from Tb 3+ combined with weak ferromagnetism from Fe 3+ spin canting.