Study of La-doped barium titanate ceramics obtained by laser sintering technique

This work studies the influence of laser sintering on the semiconducting properties of La-doped BaTiO3 (BTL) ceramics. The BTL powders were synthesized using a solid-state reaction method and sintered via a new laser sintering technique. In this technique, a CO2 laser is used as the main heating source and no atmosphere control was employed. The BTL laser-sintered ceramics exhibited high relative density and a crack-free homogeneous microstructures after sintering at a laser power density of 5.0W/mm(2) for 30s. The samples exhibited a positive temperature coefficient of resistivity (PTCR) increase of two orders of magnitude, and a room-temperature resistivity of 10(5)Omega.cm, even when sintered in an open atmosphere. X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, and UV-Vis and impedance spectroscopy techniques were employed and results provided.