Effect of Ar+ irradiation on the electrical conductivity of BaCe0.9Y0.1O3−δ

• Published in: Applied surface science Vol. 257; no. 21; pp. 8876 - 8882
• Main Authors: Kim, Jae-Hwan, Choi, Heekyu, Shikama, Tatsuo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 15.08.2011
• Subjects: Air conditioning; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fluence; Impedance measurement; Irradiation; Physics; Scanning electron microscopy; Vacancies; X-ray photoelectron spectroscopy; Ar; Surface modification; Electrical conductivity; Physical radiation effects; Ionic conductors; Proton conductivity; Surface treatments; ERDA; ion fluence
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2011.04.136

The effects of 10 keV Ar+ ion irradiation on the electrical characteristics of BaCe0.9Y0.1O2.95 subject to fluences of 0, 1.0 x 10 exp(17), 5.0 x 10 exp(17) and 1.0 x 10 exp(18) ions/cm2 at room temperature, were investigated using ERDA, SEM, EDX, XPS and AC impedance measurements. The ERDA results show that the hydrogen concentration near the surface increased with increasing Ar+ ion fluence, which may be associated with increasing quantities of hydrogen generated by the interaction between oxygen vacancies, formed by irradiation, and H2O from exposure to air. SEM images showed that the number of surface defects due to modification increased with increasing fluence. The size of the defects also showed a tendency to increase with increasing fluence. From the results of XPS analyses, providing information on the electronic states on the surface, it was evident that with increase in the Ar+ ion fluence, the quantity of excess oxygen, such as hydroxide, increased in the oxygen 1s XPS spectrum. It was also indirectly found, from decomposition of the Ce 3d spectrum, that the concentration of oxygen vacancies increased with fluence, since the percentage of Ce3+ also increased. The surface modification led to the formation of more oxygen vacancies and a greater hydrogen concentration on the surface, as the H2O interacted with some of them. The DC conductivity and AC impedance measurements showed that the proton conductivity predominated over the temperature range from 473 K to 823 K. It was concluded that the increase in these protons and vacancies generated from surface modification contributed to the increase of proton conductivity.