Effects of alumina nano-particulates addition on mechanical and electrical properties of barium titanate ceramics

Ferroelectric BaTiO3/xAl2O3 nanocomposite ceramics (when x = 0, 0.5, 1, 3 and 5 vol%) were fabricated from an in-house prepared BaTiO3 powder and nano-sized Al2O3 powder by a solid state mixed-oxide method. Densities and grain sizes of the ceramics were found to gradually decrease with increasing content of Al2O3 addition. Mechanical properties such as Knoop hardness and Young's modulus of BaTiO3 were found to be improved with only 0.5 vol% of Al2O3 addition. Dielectric and piezoelectric properties of the nanocomposites with <1 vol% Al2O3 addition could be maintained and were comparable to the values of the monolithic BaTiO3. Within the range of the BaTiO3/Al2O3 nanocomposites investigated, this study suggested materials with acceptable electrical properties and better structural stability.