Magnetically roll-oriented LaFeO sub(3) nanospheres prepared using oxalic acid precursor method

• Published in: Journal of materials science. Materials in electronics 2015-02, Vol.26 (2), p.1045-1052
• Main Authors: Salah, L M, Rashad, M M, Haroun, M, Rasly, M, Soliman, MA
• Format: Article
• Language: English
• Subjects: Anisotropy; Annealing; Ferromagnetism; Lanthanum; Magnetic properties; Oxalic acid; Precursors; Relaxation time
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-014-2503-0

Roll-oriented lanthanum orthoferrite LaFeO sub(3) powders have been successfully synthesized using oxalic acid precursor method. Well crystalline LaFeO sub(3) phase was obtained at different annealing temperatures from 600 to 1,000 degree C for 2 h. FT-IR spectrum indicated that two active vibrational bands were assigned at 555 and 400 cm super(-1) imputed the formation of lanthanum orthoferrite. The average particle size of LaFeO sub(3) powders were ranged from 50 to 150 nm. The magnetic properties of LaFeO sub(3) samples exhibited a weak ferromagnetic behavior at the room temperature. The shape and surface interface anisotropy were so far strong forming a roll-orientation of particles. The interplay between magnetic properties and annealing temperature showed that the low magnetic interactions between particles were observed as the result of large particles size produced and low surface-interface anisotropy occurred. Hence, microstructures were gradually transformed to tube- and then fibrous-like structures with increasing the annealing temperature. Results are explained in basis of spin-orbit interactions between particles. Furthermore, analysis of the AC electrical data in impedance and dielectric permittivity formalisms revealed the presence of three relaxation processes in LaFeO sub(3), with sufficiently different relaxation times.