Effects of combustion agents on the synthesis of perovskite erbium ferrite (ErFeO3) nanocrystalline powders fabricated by auto-propagating combustion process

Orthorhombic perovskite-type ErFeO3 nanocrystalline powders were successfully prepared by sol-gel auto-combustion method using different combustion agents (alanine, citric acid and urea) at rather low combustion temperatures. The phase identification, thermal analysis, Fourier transform infrared spectra, morphology, surface area/pore volume, element valence state and magnetic properties of synthesized powders were studied systematically. The as-prepared ErFeO3 nanocrystalline powders exhibited sphere-like shape with continuous porous network structure attributing to the releasing of a large amount of gases during auto-combustion process. Both the citric acid and urea combustion agents are beneficial for producing the large surface area and porous ErFeO(3 )nanocrystalline powders. The ErFeO3 powders exhibited ferrimagnetic feature at low temperatures, and the magnetization reaches 80.0 emu/g at 10 K. The ErFeO3 powders have a transition from antiferromagnetism to paramagnetism with increasing ambient temperatures. As the ambient temperature is 300 K, the magnetization of ErFeO3 powders is only 7.4 emu/g.