⁵⁷Fe Mössbauer spectra study of coated α-Fe₂O₃ nanoparticles

Abstract

Nano-sized α-Fe₂O₃ particles coated with polar organic molecules have been studied using the Mössbauer spectroscopy method. The α-Fe₂O₃ nanoparticles were prepared by the microemulsion method. The average particle size of the Fe₂O₃ particles is about 24 Å. Because the particle size is so small that the Mössbauer spectra of the α-Fe₂O₃ samples only consist of a quadrupole-split central line. It was proved that the Isomer Shifts (DIS) and the Quadrupole Splitting (DQS) changed as the refluxing time prolongs and the refluxing temperature increases during the preparation of the Fe₂O₃ nanoparticles, which implied an enhancement of the surface electrofield gradient formed by the surface coated polar molecules during the refluxing process.