Effects of Pt dispersion on electronic and oxide ionic conductivity in Pr1.90Ni0.71Cu0.24Ga0.05O4

Abstract

The effects of dispersing Pt particles in bulk Pr_1.90Ni_0.71Cu_0.21Ga_0.05O_4+δ (PNCG) on the electrical conductivity and oxygen permeability of the material were studied. The different thermal expansion coefficients of PNCG and Pt generated a mechanical compressive strain in the PNCG. This may cause the electrical conductivity to decrease in samples containing Pt. In contrast, the oxide ion conductivity estimated from the oxygen permeability increased upon dispersion of Pt. These variations appear to be related to the electron hole and interstitial oxygen concentrations. Moreover, the present study suggests that the mechanical strain induces a chemical strain via the introduction of oxygen defects as well as changes in cation valences.