Scheelite-type Ca1-xSmxMoO4+delta electrolyte powders were prepared by the sol-gel auto-combustion process. The crystal structure of the samples was determined by employing the techniques of X-ray diffraction (XRD). According to the XRD analysis, the formed continuous series of Ca1-xSmxMoO4+delta (0 <= x <= 0.3) solid solutions had the structure of tetragonal scheelite, and the lattice parameters increased with increasing x in the Sm-substituted system. Results of sinterability and electrochemical testing revealed that the performances of Sm-doped calcium molybdate were superior to that of pure CaMoO4. Ca1-xSmxMoO4+delta ceramics show higher sinterability, and the Ca0.8Sm0.2MoO4+delta sample with 98.7% of the theoretical density were obtained after being sintered at 1250 degrees C for 4 h. The conductivity increased with increasing samarium content, and a total conductivity 9.54 x 10(-3) S cm(-1) at 800 degrees C could be obtained in Ca0.8Sm0.2MoO4+delta sintered at 1250 degrees C for 4 h. (C) 2010 Elsevier Ltd. All rights reserved.