Sintering and electrical properties of lead-free Na0.5K0.5NbO3 piezoelectric ceramics
Sintering and electrical properties of lead-free Na0.5K0.5NbO3 piezoelectric ceramics
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DOI：
10.1111/j.1551-2916.2006.00991.x
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发表时间：
2006-06-01
影响因子：
3.9
通讯作者：
Li, Longtu
中科院分区：
文献类型：
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作者：
Zuo, Ruzhong;Roedel, Juergen;Li, Longtu
无铅Na_（0.5）K_（0.5）NbO_3（NKN）压电陶瓷在相对较低的温度下在大气条件下相当好地致密化。96%-99%的相对密度可以通过使用高能研磨或添加1摩尔%的氧化物添加剂来实现。研究表明，活性球磨法制备的超细起始粉末或氧空位，甚至B位氧化物添加剂形成的液相，是改善烧结的主要因素。氧化物添加剂不仅影响介电性能，如居里温度（T-c）和介电损耗（D），而且还改变铁电性。产生了相对较大的反射极化，范围从纯NKN的16 μ C/cm（2）到添加ZnO的NKN样品的23 μ C/cm（2）。获得了如下介电和压电性能：相对介电常数ε（T）（33）/ε（0）=570-650，平面模式机电耦合因子k（p）=32%-44%，压电应变常数d（33）=92-117 pC/N。
Lead-free Na0.5K0.5NbO3 (NKN) piezoelectric ceramics were fairly well densified at a relatively low temperature under atmospheric conditions. A relative density of 96%-99% can be achieved by either using high-energy attrition milling or adding 1 mol% oxide additives. It is suggested that ultra-fine starting powders by active milling or oxygen vacancies and even liquid phases from B-site oxide additives mainly lead to improved sintering. Not only were dielectric properties influenced by oxide additives, such as the Curie temperature (T-c) and dielectric loss (D), but also the ferroelectricity was modified. A relatively large remanent polarization was produced, ranging from 16 mu C/cm(2) for pure NKN to 23 mu C/cm(2) for ZnO-added NKN samples. The following dielectric and piezoelectric properties were obtained: relative permittivity epsilon(T)(33)/epsilon(0)=570-650, planar mode electromechanical coupling factor, k(p)=32%-44%, and piezoelectric strain constant, d(33)=92-117 pC/N.