Physicochemical properties of electrode materials based on substituted yttrium manganite

Electrode materials Y0.5Ca0.5Mn1−x(Co,Ni)xO3(x = 0–0.1) have an o′-orthorhombic perovskite structure. Doping with transition metals raises the content of ions Mn4+ from 49% at x = 0 to 62% at x = 0.05 Ni. At 500–650 K there takes place an o′-o-orthorhombic transition, with the thermal expansion coefficient rising from (7.1–8.1) × 10−6 to (10.5–11) × 10−6 K−1. Composition Y0.5Ca0.5Mn1–x(Co, Ni)xO3 is n-type semiconductor with a considerable oxygen constituent at >1000 K. Effect of the electrode material composition on the resistance parameter (ρ/d) of an intermediate layer E/SE and on the polarization resistance (Rη) of the triple-phase boundary E/SE/GP is similar. At 300–1100 K and 102–105 Pa, minimum values of these quantities are exhibited by samples with the Y0.5Ca0.5Mn0.95Ni0.05O3 electrode layer 50 mg cm−2 thick.