Reduction of microcracking in YMnO3 ceramics by Ti substitution

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.