Mixed conductivity of zircon-type Ce(1-x)A(x)VO(4 +/-delta) (A = Ca, Sr)


Incorporation of alkaline-earth cations into the zircon-type lattice of Ce(1-x)A(x)VO(4+delta) (A = Ca, Sr; x = 0 - 0.2) was found to significantly increase the p-type electronic conductivity and to decrease the Seebeck coefficient, which becomes negative at x greater than or equal to 0.1. The oxygen ionic conductivity is essentially unaffected by doping. The ion transference numbers of Ce(1-x)A(x)VO(4+delta) in air, determined by the faradaic efficiency measurements, are in the range from 2 x 10(-4) to 6 x 10(-3) at 973-1223 K, increasing when temperature increases or alkaline-earth cation content decreases. The results on the partial conductivities and Seebeck coefficient suggest the presence of hyperstoichiometric oxygen, responsible for ionic transport, in the lattice of doped cerium vanadates. The activation energies for the electron-hole and ionic conduction both decrease on doping and vary in the ranges 39-45 kJ/mol and 87-112 kJ/mol, respectively.




Chemistry; Electrochemistry; Physics


Tsipis, EV; Kharton, VV; Vyshatko, NP; Shaula, AL; Patrakeev, MV; Frade, JR

nossos autores

Partilhe este projeto

Publicações similares

Usamos cookies para atividades de marketing e para lhe oferecer uma melhor experiência de navegação. Ao clicar em “Aceitar Cookies” você concorda com nossa política de cookies. Leia sobre como usamos cookies clicando em "Política de Privacidade e Cookies".