Electron Spin Resonance and Atomic Force Microscopy Study on Gadolinium Doped Ceria

Abstract

A combined electron spin resonance (ESR) and atomic force microscopy (AFM) study on Ce1−xGdxO2−x/2samples is here presented, aimed at investigating the evolution of the ESR spectral shape as a function ofxin a wide composition range. At lowx=0.02, the spectrum is composed of features atgeff≈2; 2.8; 6. With increasingx, this pattern merges into a singlegeff≈2broad ESR curve, which assumes a Dysonian-shaped profile atx≥0.5, whereas, at thesexvalues, AFM measurements show an increasing surface roughness. It is suggested that the last could cause the formation of surface polaritons at the origin of the particular ESR spectral profile observed at these high Gd doping levels.