fig4

Figure 4. (A) The complex impedance plot obtained at 600 °C in Ar of Ca_1.46Ti_1.38Nb_1.11O₇; (B) The complex impedance plot obtained at 600 °C in air of Ca_1.46Ti_1.38Nb_1.11O₇; (C) The complex impedance plot obtained at 600 °C in 5% H₂/Ar of Ca_1.46Ti_1.38Nb_1.11O₇; (D) The total conductivity σ_b+gb of Ca_1.46Ti_1.38Nb_1.11O₇ in the range of 500-900 °C in 5% H₂/Ar, Ar, and air (data from impedance curve fitting).