Concentration dependence of magnetic moment in Ce1-xFexO2

Geoffrey L. Beausoleil, Aaron Thurber, S. S. Rao, Gordon Alanko, C. B. Hanna, Alex Punnoose
2012 Journal of Applied Physics  
In this study, we examined the impact of iron doping on the structural, chemical, and magnetic properties of ceria (Ce 1-x Fe x O 2 ). Samples were produced in triplicate through a coprecipitation approach in a forced hydrolysis synthesis that yielded consistently sized nanocrystals, using three different cerium precursors: cerium chloride, cerium ammonium nitrate and cerium nitrate. Particles were characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), transmission
more » ... S), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR) spectroscopy and vibrating sample magnetometry (VSM). XRD showed the average crystallite size to be 4.4 ± 1.2 nm, which agreed well with TEM data. XPS and EPR data shows iron to be in the Fe 3+ state and confirms the nominal dopant concentration. The moment per Fe ion found was largest at the lowest dopant concentrations, with values of 0.078 and 0.055 µ B /Fe ion for 0.1 and 0.5% Fe, respectively, which quickly decreased as the concentration was increased. We used XPS to estimate Ce 3+ /Ce 4+ ratio to be in the 0.2-0.3 range and observed a linear relation between the saturation magnetization and the Ce 3+ /Ce 4+ ratio.
doi:10.1063/1.3688933 fatcat:7piilfjw6jablgfvoxvwadk6wa