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.

Percolating hierarchical defect structures drive phase transformation in Ce1−xGdxO2−x/2: a total scattering study

“…The fitting performed on Ce 1Àx Gd x O 2Àx/2 spectra to extract quantitative parameters using a single Lorentzian or Gaussian function generally gave poor results, as observed previously (Oliva et al, 2004). The Dysonian line shape (Joshi & Bhat, 2004;Allieta et al, 2013;Oliva et al, 2015) including more parameters provided a more satisfactory description of the ESR line shapes but only for x Gd ! 0.375.…”

Local and Average Structure of Yb-Doped Ceria through Synchrotron and Neutron Pair Distribution Function

“…Ce 1−µ Yb µ O 2−µ/2 samples with µ = 0, 0.125, 0.250, 0.375, and 0.500 were produced using a modified Pechini sol-gel procedure, as described in [45]. Ce(NO 3 ) 3 ·6H 2 O (99%) and Yb(NO 3 ) 3 ·5H 2 O (99.9%) were dissolved into water in due proportions; then an excess of citric acid (99%) and ethylene glycol (≥99%) was added to the solution.…”