Crystal Structure and Piezoelectric Properties of KNbO3-BiFeO3 Ceramics

다국어 초록 (Multilingual Abstract)

The crystal structure, microstructure, and piezoelectric properties of 1-wt% MnO-doped (1 - x)KNbO₃-xBiFeO₃ (x = 0 ∼ 0.05) ceramics were investigated. The crystal structure changed from orthorhombic to pseudo-cubic around x = 0.005 in the (1 - x)KNbO₃-xBiFeO₃ ceramics. The addition of BiFeO₃ to KNbO₃ reduced the grain size and led to poor densification. The Dielectric constant showed a maximum at x = 0.005 where the crystal structure changed. The KNbO₃ ceramic had a pinched P-E hysteresis loop. KNbO₃-BiFeO₃ ceramics had lower remanent polarizations (P_r) than KNbO₃, probably due to the effect of small grain size. The KNbO₃ ceramic showed good piezoelectric properties; a planar electromechanical factor (k_p) of 0.304, a mechanical quality factor (Q_m) of 281, and a piezoelectric constant (d₃₃) of 121 pC/N. The KNbO₃-BiFeO₃ ceramic, however, had inferior piezoelectric properties compared to KNbO₃ due to the incomplete poling resulting from the small grain size, low density, and low insulating resistance.

참고문헌 (Reference)

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