Microstructure Evolution in Sintered CoO under Electric Fields

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J. Korean Ceram. Soc. > Volume 29(11); 1992 > Article

Journal of the Korean Ceramic Society 1992;29(11): 912.

CoO 소결체의 전기장에 의한 미세구조 변화

이기춘, 유한일

서울대학교 무기재료공학과

Microstructure Evolution in Sintered CoO under Electric Fields

ABSTRACT

Microstructure evolution including morphological change in the vicinity of the electrodes, porosity change and grain boundary migration was observed in polycrystalline CoO subject to electric fields at 1100 and 121$0^{circ}C$ in air. At the cathode, the transported cations react with oxygen in the surrounding to form new lattices, while, at the anode, the reverse reaction occurs leading to lattice annihilation. Lattice formation also takes place at the surface of pores near the cathode inducing pore-filling effect. Grain boundary migration was found bo be enhanced or retarded depending on the field direction. It is therefore implied that the driving force of grain boundary migration is the vectorial sum of the curvature-induced chemical potential gradient and the electric field applied.