Origin of high mechanical quality factor in CuO-doped (K, Na)NbO3-based ceramics

• Published in: Frontiers of materials science 2014-06, Vol.8 (2), p.165-175
• Main Authors: Liang, Wen-Feng, Xiao, Ding-Quan, Wu, Jia-Gang, Wu, Wen-Juan, Zhu, Jian-Guo
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Materials Science; Research Article
• ISSN: 2095-025X; 2095-0268
• DOI: 10.1007/s11706-014-0245-9

The origin of a high mechanical quality in CuO-doped (K, Na)NbO 3 -based ceramics is addressed by considering the correlations between the lattice positions of Cu ions and the hardening effect in K 0.48 Na 0.52 + x NbO 3 -0.01CuO ceramics. The Cu ions simultaneously occupy K/Na and Nb sites of these ceramics with x = 0 and 0.02, only occupy the K/Na site of the ceramics with x = −0.02, and mostly form a secondary phase of the ceramics with x = −0.05. The Cu ions lead to the hardening of ceramics with an increase of E C and Q m by only occupying the K/Na site, together with the formation of double hysteresis loops in un-poled compositions. A defect model is proposed to illuminate the origin of a high Q m value, that is, the domain stabilization is dominated by the content of relatively mobile O 2− ions in the ceramics, which has a weak bonding with Cu K/Na defects.