气氛烧结锂掺杂铌酸钾钠无铅压电陶瓷的电学性能

Electrical Properties of Lithium-Potassium Sodium Niobate Lead-free Piezoelectric Ceramics Sintered in a Protective Atmosphere

在工业氮气(N2)气氛条件下制备了锂掺杂铌酸钾钠(NKLN)无铅压电陶瓷,研究了Li掺杂量对陶瓷相结构、微观结构及电学性能的影响。结果表明,NKLN陶瓷具有钙钛矿结构,随Li含量的增加,陶瓷在室温下出现了从斜方相到四方相的转变;当Li含量为7%(摩尔分数)时,陶瓷具有优良的电学性能,压电常数(d33)、机电耦合系数(kp)和剩余极化强度(Pr)分别为223pC/N、38.2%和12.11μC/cm2;陶瓷的居里温度Tc随着Li含量的增加而升高,当Li含量为6%(摩尔分数)时为420℃,Li含量为8%(摩尔分数)时为480℃。

Lithium-potassium sodium niobate lead free piezoelectric ceramics（NKLN） are fabricated by protective sintering in a nitrogen gas. The effect of Li content on the phase structure, relative density and electrical properties of ceramics are investigated. The results show that NKI.N has perovskite structure. There is a change from orthorhombic to tetragonal with the increase of I.i content at room temperature. With I.i content reaching at 7mol%, the ceramics have excellent electrical properties. The piezoelectric constant alas and electromechanical coupling factor kp are 223pC/N and 38. 2%, respectively. The Curie temperature Tc increased from 420℃ for the ceramics with Li content of 6mol% to 480 for the ceramics with Li content of 8mol%. The maximum value of the remanent polarization Pr are obtained as 12. 11μC/cm^2 when the Li content was 7mol%.