The hardening of CuO–(K,Na)NbO3 via post annealing with argon
The hardening of CuO–(K,Na)NbO3 via post annealing with argon
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DOI：
10.7567/jjap.53.015503
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发表时间：
2013
影响因子：
1.5
通讯作者：
Yaoyang Liu;T. Maeda;Y. Yokouchi;T. Morita
中科院分区：
文献类型：
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作者：
Yaoyang Liu;T. Maeda;Y. Yokouchi;T. Morita
采用水热法制备了Cu掺杂的钛酸钾钠CuO-（K 0. 48 Na 0. 52）NbO 3（CuO-KNN）陶瓷。在烧结过程之后采用氩气气氛的额外后退火工艺以提高品质因数（Qm）。结果表明，氩气退火工艺可以显著提高Qm从880到约1500。在CuO-KNN陶瓷中，Cu 2+取代Nb 5+作为受主型掺杂剂，这将构成电荷偶极子。这些电荷偶极子倾向于在畴边界周围相对稳定，并产生钉扎效应。钉扎效应可以是如此之强，以至于畴壁变得更难以移动，即使在外加电场下。因此，退火过程可以增加氧空位的量，这影响了畴结构的稳定性。氧空位的增加加强了对畴壁运动的抑制，从而增大了Qm值。
Copper-doped potassium sodium niobate CuO–(K0.48Na0.52)NbO3 (CuO–KNN) ceramics was fabricated via a hydrothermal method. An extra post-annealing process with argon atmosphere was adopted after the sintering procedure to increase the quality factor (Qm). The results show that the annealing process with argon can significantly increase the Qm from 880 to approximately 1500. In CuO–KNN ceramics, Cu2+ substitutes Nb5+ as an acceptor type dopant, which would constitute charge dipoles. These charge dipoles are inclined to be relatively stable around the domain boundaries and generate a pinning effect. The pinning effect can be so strong that the domain walls become more difficult to move, even under applied electric field. Thus, the annealing procedure can increase the amount of oxygen vacancies, which influences the stability of the domain structures. The increase of oxygen vacancies strengthens the suppression of domain wall movement and thus enlarges the Qm value.