Samples of Zr-doped and undoped polycrystalline material were used to study the effects of Zr doping upon the structure and conductivity. It was found that less than 1at%Zr was sufficient to stabilize the tetragonal structure. The conductivity of the Zr-doped samples was measured at temperatures of between 200 to 550C (table 136) by using alternating current complex impedance analysis. Undoped material had the best conductivity, which was equal to 0.003S/cm at 400C.

Y.Zou, A.Petric: Materials Research Bulletin, 1993, 28[6], 1169-75