Structural and electrical characterization of the series La1.33NaxMnxTi2-xO6

A new series of perovskite-type materials of general formula La1.33NaxMnxTi 2-xO6 (x = 0.66, 0.55 and 0.44) was obtained and characterized. The common structure is rhombohedral (space group R (3) over bar c) although a transit ion to orthorhombic (space group Ibmm) is observed between 400 and 600 K fo r the x = 0.66 phase. Complex impedance techniques and charge/discharge cyc les show a different electrical behavior that varies from a purely electron ic conductor (x = 0.66) to a mixed electronic-ionic behavior for the other phases.