Electrical properties of ferroelectric BaTi2O5 and dielectric Ba6Ti17O40 ceramics -: art. no. 084104

Single phase powders of BaTi2O5 and Ba6Ti17O40 were made by a sol-gel method with final heating at 1100-1200 degrees C. Ceramic samples were prepared and fired at temperatures in the range 1100-1300 degrees C. Both sets were highly insulating, with conductivities of, e.g., 10(-6)-10(-7) S cm(-1) at 600 degrees C and activation energies for conduction in the range 1.75-1.86 eV. BaTi2O5 compositions are ferroelectric with a permittivity maximum dependent on firing conditions: epsilon(max)'=122 at 450 degrees C on firing at 1100 degrees C; and epsilon(max)'=130 at 475 degrees C on firing at 1225 degrees C. Ba6Ti17O40 is a dielectric with epsilon(')similar to 57-55 over the range 40-400 degrees C. (C) 2005 American Institute of Physics.