resumo
In this work, we revisit the phase transition sequence and the effect of the sintering process on the structural, dielectric and polar properties of K0.5Na0.5NbO3 ceramics prepared by conventional sintering, spark plasma sintering and spark plasma texturing. Herein, comparative experimental study of the lattice dynamics, polar and dielectric properties is presented. We observe that the phase transition sequence includes an unreported structural and polar phase at low temperatures, independently on the processing method. Contrarily, we observe apparent changes of the stability temperature interval of the different phases. The dielectric strength and the emergence of a dielectric relaxation phenomenon are also noticeably dependent on the processing method, which can be understood as an effect of the different grain size. The results here reported clearly show the possibility to change physical properties following different sintering routes in order to improve device performance.
categoria
Materials Science, Ceramics
autores
Gomes, MM; Vilarinho, R; Pinho, R; Almeida, A; Noudem, JG; Costa, MEV; Vilarinho, PM; Moreira, JA
nossos autores
Maria Elisabete Jorge Vieira Costa
Colaborador
Paula Maria Lousada Silveirinha Vilarinho
Vice-Diretor
Rui Manuel de Oliveira Pinho
Estudante de doutoramentoagradecimentos
This work was developed within the scope of the projects UIDB/50011/2020 and UIDP/50011/2020, of CICECO-Aveiro Institute of Materials and NORTE-01-0145-FEDER-022096 and UID/NAN/50024/2019, of IFIMUP. Mariana Gomes and Rui Pinho acknowledge the projects PTDC/NAN-MAT/28538/2017 and FCT for financial support SFRH/BD/120969/2016, respectively.