Scheelite-type, LaxCa1-xMoO4+delta electrolyte powders, are prepared by the sol-gel process. The crystal structure of the samples is determined by employing the technique of X-ray diffraction (XRD). According to XRD analysis, the continuous series of LaxCa1-xMoO4+delta (0 <= x <= 0.3) solid solutions have the structure of tetragonal scheelite. Their lattice parameters are greater than that of the original sample, and increase with increasing values of x in the La-substituted system. Results of sinterability and electrochemical testing reveal that the performances of La-doped calcium molybdate are superior to that of pure CaMoO4. LaxCa1-xMoO4+delta ceramics' demonstrate higher sinterability. The La0.2Ca0.8MoO4+delta sample that achieved 96.5% of the theoretical density was obtained after being sintered at 1250 degrees C for 4h. The conductivity increases with increasing lanthanum content, and a total conductivity of 7.3 x 10(-3) Scm(-1) at 800 degrees C could be obtained in the La0.2Ca0.8MoO4+delta compound sintered at 1250 degrees C for 4 h. (C) 2009 Elsevier B.V. All rights reserved