Lead-Free Barium Titanate Ceramics with Large Piezoelectric Constant Fabricated by Microwave Sintering

Abstract

A lead-free barium titanate (BaTiO 3 ) ceramics with a high density and a large piezoelectric constant, d 33 , as manufactured at 1320°C by microwave sintering, using a pure fine powder with a particle size of 100 nm produced by hydrothermal synthesis. The density of the ceramic with a 3.4 µm grain size was more than 98.3% of the theoretical value. The ceramic after poling had a dielectric constant of ε 33 T / ε 0 =4200, an electromechanical coupling factor planar mode of k p =36% and d 33 =350 pC/N. The value of d 33 is the largest one ever reported for lead-free BaTiO 3 ceramics.