Effects of dopants on grain growth of nano-sized BaTiO3 powders prepared by citric acid-assisted spray pyrolysis

Nano-sized BaTiO3 powders doped with Y, Eu and La components were prepared by ultrasonic spray pyrolysis from a spray solution with citric acid. The precursor BaTiO3 powders had a large size, fractured and hollow structures irrespective of the type of dopant. The calcined BaTiO3 powders with and without dopants had nanometre sizes after a simple milling by hand using an agate mortar. The mean size of La-doped BaTiO3 powders measured from the transmission electron microscope (TEM) images was 38 nm at a calcination temperature of 700 degrees C. The mean crystallite sizes of the doped and undoped BaTiO3 powders changed from 20 to 33 nm according to the type of dopant at a calcination temperature of 700 degrees C. An effective grain growth inhibition took place with the doped BaTiO3 ceramics. The average grain sizes of La and Eu-doped BaTiO3 ceramics were each 380 and 400 nm at a sintering temperature of 1280 degrees C.