Sintering mechanism and dielectric properties of LiTaO3 matrix composites with the addition of Al2O3 particles

Highly densified Al2O3/LiTaO3 (ALT) ceramic composites were fabricated by hot-pressing in a nitrogen atmosphere. The addition of Al2O3 particles could significantly improve the densification of LiTaO3. Sintering mechanism of the LiTaO3 ceramic incorporated with Al2O3 particles is proposed. Dielectric constant of 5 vol.% Al2O3/LiTaO3 (5ALT) composite ceramic was slightly increased in the range from 30 kHz to 106 Hz, but the dielectric loss was lowered in the whole range from 103 Hz to 106 Hz. Piezoelectric constant (d33) of the 5ALT ceramic composite is about 50% of that of LiTaO3 single crystal.