The present work is devoted to the investigation of two series of doped bismuth molybdates: Bi26-2xMn2xMo10O69-d and Bi26Mo10-2yMn2yO69-d. Complex oxides were synthesized by conventional solid state technology and by co-precipitation method. The products were identified by powder diffraction. The powders and ceramic samples were examined by means of densitometry, laser diffraction, and electron microscopic methods. Porosity of the ceramic materials was estimated using the hydrostatic method. The electrical conductivity measurements were carried out using impedance spectroscopy method., {"references": ["J. C. Boivin, \"Structural and electrochemical features of fast oxide ion conductors,\" Int. J. Inorg. Mat., vol. 3, pp. 1261-1266, Dec. 2001.", "F. Abraham, J. C. Boivin, G. Mairesse and G. Nowogrocki, \"The bimevox series: a new family of high performances oxide ion conductors,\" Solid State Ionics, vol. 40-41, pp. 934-937, Aug. 1990.", "R. Enjalbert, G. Hasselmann and J. Galy, \"(Bi12O14E12)n Columns and lone pairs E in Bi13Mo4VO34E13: synthesis, crystal structure, and chemistry of the Bi2O3\u2013MoO3\u2013V2O5 system\", J. Solid State Chem., vol. 131, pp. 236-245, July 1997.", "D. J. Buttrey, T. Vogt, G. P. A Yap and A. L. Rheingold, \"The structure of Bi26Mo10O69\", Mater. Res. Bull., vol. 32, no. 7, pp. 947-962, July 1997.", "R. N. Vannier, G. Mairesse, F. Abraham and G. Nowogrocki, \"Bi26Mo10O\u03b4 solid solution type in the Bi2O3\u2013MoO3\u2013V2O5 ternary diagram\", J. Solid State Chem. vol. 122, no.2, pp. 394-406, Mar. 1996.", "J. Galy, R. Enjalbert, P. Rozier and P. Millet, \"Lone pair stereoactivity versus anionic conductivity. Columnar structures in the Bi2O3\u2013MoO3 system\", Solid State Sci. vol. 5, no.1, pp. 165\u2013174. Jan. 2003.", "C. D. Ling, W. Miiller, M. R. Johnson, D. Richard, S.Rols, J. Madge et al., \"Local structure, dynamics, and the mechanisms of oxide ionic conduction in Bi26Mo10O69\", Chem. Mater. vol. 24, pp. 4607\u22124614, Nov. 2012.", "B. Bastide, S. Villain, P. Salles and J. Galy, \"Oxygen diffusion pathway in the anionic conductor Bi26Mo9GeO68\", Solid State Sci. \u2013vol. 4, no. 5, pp. 599-608, Apr. 2002.", "R. N. Vannier, S. Danz\u00e9., G. Nowogrocki, M. Huve and G. Mairesse, \"A new class of mono-dimensional bismuth-based oxide anion conductors with a structure based on (Bi12O14)\u221e columns\", Solid State Ionics, vol. 136-137, pp. 51-59. Nov. 2000.\n[10]\tJ. Galy, P. Salles, P. Rozier, A. Castro, \"Anionic conductors Ln2/3(Bi12O14)(MoO4)5 with Ln=La, Nd, Gd, Ho, Yb. Synthesis\u2013spark plasma sintering\u2013structure\u2013electric properties\", Solid State Ionics, vol. 177, no. 33-34, pp. 2897-2902, Nov. 2006.\n[11]\tR. Enjalbert, G. Hasselmann, J. Galy, \"A new mixed oxide with (Bi12O14)n columns: PbBi12Mo5O34\", Acta Crystallgr. Sect.C, vol. 53, no. 3, pp.. 269-272, Mar. 1997.\n[12]\tB. Muktha, T. N. Guru Row, \"Crystal structure and ionic conductivity of the series A2Bi24Mo8X2O68 (A=Ca, Sr and Ba and X=Cr, W)\", Struct. Chem., vol. 18, pp. 195-202, Dec. 2007.\n[13]\tA. Castro, R. Enjalbert, P. Baules, J. Galy, \"A. Synthesis and Structural Evolution of the Solid Solution Bi(Bi12\u2212xTexO14)Mo4\u2212xV1+xO20 (0\u2264x