Oxygen-permeation measurements were carried out on a Gd0.85Ca0.15AlO3−δ specimen at 400 to 900C as a function of the O partial pressure from 1.01 x 105 to 18.85Pa. Simultaneously, the open-circuit voltage of the permeation cell and the voltage upon partially short-circuiting the cell over external resistances were measured. As a result, the ionic conductivity of Gd0.85Ca0.15AlO3−δ between 650 and 900C and the electronic conduction parameter of the hole conductivity were obtained as a function of temperature. The electrochemical performance as well as the stability of the electrolyte material were studied by carrying out cell-voltage measurements under Ar+1000ppmH2 (anode) and air (cathode) environments. The present investigations suggest that Gd0.85Ca0.15AlO3−δ was predominantly an O-ion conductor with an ionic conductivity slightly below that of yttria-stabilized zirconia.

Study on Ionic and Electronic Transport Properties of Calcium-Doped GdAlO3. A.Sinha, H.Näfe, B.P.Sharma, P.Gopalan: Journal of the Electrochemical Society, 2008, 155[3], B309-14