resumo
Microcracking in YMnO3 ceramics originates from a combination of 3.7% volume change and strong anisotropy in the thermal expansion coefficient of the hexagonal structure. In this paper, the effect of Ti doping on the microstructure, structure and dielectric response of YMnO3 ceramics is studied. Lattice anisotropy of the hexagonal cell markedly decreased with increasing Ti, reducing the residual stresses created at the high-temperature phase transition and commensurately decreasing the crack density (3.2 vol.% YMnO3 to 0.9 vol.% YMn0.9Ti0.1O3). These results represent the first systematic work to reduce microcracking in YMnO3-based ceramics. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
palavras-chave
THERMAL-EXPANSION ANISOTROPY; ORIGIN
categoria
Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering
autores
Tomczyk, M; Senos, AMOR; Reaney, IM; Vilarinho, PM
nossos autores
Grupos
2 - nanoestruturas e cerâmicos ferróicos multifuncionais
3 - materiais de carbono, compósitos e revestimentos funcionais
agradecimentos
The authors acknowledge the financial support from FEDER, QREN, COMPETE, and FCT within the project PTDC/CTM/67575/2006.