Effect of laser irradiation on lithium niobate powders

Abstract

LiNbO3 is a well-known material with high potential for many technological applications. However, conventional preparation techniques require high processing times at high temperatures. In this work, a new and fast approach is proposed, based on laser technology, envisaging obtaining bulk materials of LiNbO3. ´powders. The influence of the laser processing parameters, namely time and incident power beam, on the structure and morphology of the material was investigated and compared with the ones obtained from conventional heat treatment process.The results revealed a net dependence of LiNbO3 crystals’ morphology with both laser power and irradiation time. Increasing the time of irradiation new crystalline phases are promoted (Li3NbO4, Li0,585NbO3 and an “CaNb2O6” isostructural type), which were also detected on samples prepared by the conventional heat treatment process in an air-atmosphere furnace. Moreover, similar morphologies can be also obtained using conventional heat treatment and laser processing. The expected characteristics of LiNbO3 commercial powder (crystalline habit and size) were obtained for the based samples through laser irradiation under 6 W/1000s and through heat-treatments under 1000°C/24h. The laser processing proved to be a suitable technique to form LiNbO3 crystalline powders in a much more reduced time and also provides enough flexibility for tuning locally the grains size and morphology, allowing obtaining a morphological/structural radial gradient in a single step.