Highly orientated Bi4Ti3O12 piezoceramics prepared by pressureless sintering

Bismuth titanate (Bi4Ti3O12) has great potential for applications over 400 degrees C owning to its great Curie temperature (TC 675 degrees C). But the relatively low piezoelectric constant d(33) (< 8 pC/N) has restricted the practical high-temperature application. In this work, a new combination of the molten salt method and pressureless sintering was used to prepare textured Bi4Ti3O12 piezoceramics with a high degree of grain orientation (f = 0.83), large d(33) (29.7 pC/N) with a comparatively high TC (628 degrees C). These demonstrate that the combination is a low cost, effective and simple way to achieve highly orientated BIT ceramics with excellent performance. The mechanism and origin of the grain orientation have been deeply investigated, and the compression pressure during the molding process is proposed to be the main driving force for grain orientation, which would be very helpful for guiding the design and fabrication of novel highly orientated materials.

Automated summary

In this study, a new combination of the molten salt method and pressureless sintering was used to prepare textured Bi4Ti3O12 piezoceramics with a high degree of grain orientation, large piezoelectric constant, and high Curie temperature. The compression pressure during the molding process was proposed as the main driving force for grain orientation.