CAJ | 학술논문

采用固相反应法制备了K_(0.44)Na_(0.52)Li_(0.04)Nb_(0.86)Ta_(0.10)Sb_(0.04)O_3+x mol %K_4CuNb_8O_(23)(0≤x≤2)(简称LF4-KCN)无铅压电陶瓷,使用XRD、SEM、 Agilent 4294A精密阻抗分析仪等对该体系的相组成、显微结构、压电及介电等性能进行表征.XRD分析表明,随着KCN含量的增加,室温时样品由四方相向正交相转变,且当x≥1时,出现K_6Li_4Nb_(10)O_(30)杂相.SEM分析表明,掺入KCN后,样品晶粒尺寸减小,晶粒轮廓清晰.随着KCN含量的增加,在100 ℃附近的介电常数温度曲线上出现第二介电常数极大值,即正交→四方铁电相变温度T_(O-T),同时居里温度TC向低温方向移动.KCN掺杂量对LF4的电性能有很大影响,表现为"硬性"掺杂,其压电常数d_(33),平面机电耦合系数k_p,1kHz频率下的介电损耗tanδ和介电常数ε_r均随着 KCN含量的增加而降低,而机械品质因素Q_m整体提高,样品的密度也显著增大.
채용고상반응법제비료K_(0.44)Na_(0.52)Li_(0.04)Nb_(0.86)Ta_(0.10)Sb_(0.04)O_3+x mol %K_4CuNb_8O_(23)(0≤x≤2)(간칭LF4-KCN)무연압전도자,사용XRD、SEM、 Agilent 4294A정밀조항분석의등대해체계적상조성、현미결구、압전급개전등성능진행표정.XRD분석표명,수착KCN함량적증가,실온시양품유사방상향정교상전변,차당x≥1시,출현K_6Li_4Nb_(10)O_(30)잡상.SEM분석표명,참입KCN후,양품정립척촌감소,정립륜곽청석.수착KCN함량적증가,재100 ℃부근적개전상수온도곡선상출현제이개전상수겁대치,즉정교→사방철전상변온도T_(O-T),동시거리온도TC향저온방향이동.KCN참잡량대LF4적전성능유흔대영향,표현위"경성"참잡,기압전상수d_(33),평면궤전우합계수k_p,1kHz빈솔하적개전손모tanδ화개전상수ε_r균수착 KCN함량적증가이강저,이궤계품질인소Q_m정체제고,양품적밀도야현저증대.
The K_(0.44)Na_(0.52)Li_(0.04)Nb_(0.86)Ta_(0.10)Sb_(0.04)O_3+x mol%K_4CuNb_8O_(23)(0≤x≤2)(abbreviated as LF4-KCN) lead-free piezoelectric ceramics were fabricated by solid state reaction. The phase, microstructure, electric properties of the samples were characterized by XRD, SEM and Agilent 4294A impedance analyzer. XRD result shows that the phase of the sample transforms from tetragonal into orthorhombic with the increasing of KCN content. When x≥1, the trace amount of second phase K_6Li_4Nb_(10)O_(30) can be detected. SEM shows that the grain size of those materials decreases as the KCN content increasing, and the figure of the grain becomes clearly. There is another dielectric constant maximum value around 100 ℃, which is the phase transition from orthorhombic to tetragonal (T_(O-T)), while the curie temperature (TC) shifts to higher temperature. The KCN-doping has great influence on the electrical properties, the ceramic becomes "hardened", the piezoelectric constant (d_(33)), electromechanical planar coupling coefficients(kp), the dielectric constant(ε_r) and dielectric loss(tanδ) at 1 kHz decrease as the KCN content increasing. The mechanical quality factor (Q_m) and the density increases significantly.