Effect of mineralizer on the hydrothermal synthesis of Bi 0.5Na0.5TiO3 lead-free piezoelectric crystals

Abstract

The effect of mineralizer upon the fabrication of lead-free, piezoelectric Bi0.5Na0.5TiO3 (BNT) was investigated using a hydrothermal reaction technique. Results indicated that BNT crystals can be formed in a basic environment controlled by a NaOH mineralizer. The morphologies and sizes of the resultant particles are determined by the concentration of NaOH: a lower alkaline concentration leads to the particles with a spherical shape consisting of a number of small, intergrown BNT crystals while a higher NaOH concentration (e.g. > 12 mol/L) results in large, individual BNT cubes. Possible growth mechanisms of the BNT particles were discussed in conjunction with surface hydration, dehydration and free water content during the hydrothermal reaction. Show more