Study of hyperfine interactions in pure and Co-doped CeO2 nanoparticles by PAC spectroscopy using 111Cd

In this work we have used the Perturbed Angular Correlation (PAC) technique to measure the hyperfine interactions in pure nanostructured (crystallite size around 70 nm) as well as doped with 3d transition metal Co (3 at. %) CeO₂ samples. The PAC measurements were performed at different temperatures between 23 and 527°C. The results did not reveal any evidence of hyperfine magnetic interactions. Spectra obtained presented three major frequencies related to substitutional sites in CeO₂, grain boundary sites and intrinsic defect related sites.