resumo
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, Li-0,686NbO3 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/1000 s and through heat-treatments under 1000 degrees C/24 h. 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.
palavras-chave
GLASS; LINBO3; CRYSTALLIZATION
categoria
Materials Science
autores
Ferreira, NM; Ferro, MC; Graca, MPF; Costa, FM
nossos autores
Marta Ascenção Carmona Ferro
Técnico de Laboratório
Nuno Miguel Freitas Ferreira
Bolseiro de pós-DoutoramentoGrupos
agradecimentos
This work is funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013. Nuno Ferreira acknowledges financial support from the FCT grant SFRH/BPD/111460/2015.