Versatile synthesis of 1-D akaganeite nanoparticles with fine-tuned exchange biasing and weak ferromagnetic effect

Low dimension materials (especially antiferromagnetic nanoparticles) exhibit extraordinary magnetic properties, which are different from their bulk counterparts. Herein we report the synthesis of akaganeite nano-sticks by two different reaction pathways that enable good control on microstructure and surface properties, ensuring new application opportunities. Akaganeite nano-sticks prepared via conventional method have a length of 1.8 ± 0.15 µm and a diameter of 100 ± 20 nm with a smooth surface. Whereas modified method results in the synthesis of akaganeite nano-sticks with nanorods grown on their surface. Akaganeite nano-sticks produced by modified method have a length and diameter of 2.06 ± 0.02 µm and 160.26 ± 8.08 nm respectively. Ferromagnetism and near room temperature exchange biasing (250 K) was found in both the samples. The conventional method (AKN-0) demonstrates exchange biasing of 5700 A/m at 50 K whereas the modified method (AKN-2.5) shows 66275 A/m (approximately 11 times increased). XPS reveals defects generation in both methods, which results in the existence and enhancement of such magnetic properties. •Nanoscale antiferromagnetic materials shows different properties from their bulk counterpart.•Forced hydrolysis was used to synthesize 1-D β-FeOOH nanoparticles using two different synthesis routes.•Near room temperature exchange biasing and weak ferromagnetic effect was observed in antiferromagnetic akaganeite.•A correlation between defects generation and exchange biasing was developed and understood.