摘要:通过化学沉积方法在锆钛酸铅镧Pb1-1.5xLax(Zr0.58Ti0.42)1-1.25yNbyO3(x=0.06，y=0.02；PLZT)陶瓷颗粒表面包覆低熔点化合物氟化锂LiF和氟化铅PbF2(摩尔比1:1；PLF)，用传统固相烧结工艺制备了PLZT铁电陶瓷。研究了掺杂氟化物含量以及烧结工艺条件对PLZT陶瓷的晶相结构、微观形貌、介电、压电和铁电性能的影响。掺杂后PLZT陶瓷保持了较纯净的钙钛矿结构，陶瓷晶粒分布均匀。掺有6wt%-8wt%氟化物的PLZT陶瓷在1000℃-1100℃下烧结1小时能致密化，高温下氟化物玻璃相有扩散到PLZT主晶相的趋势。掺PLF6wt%的PLZT陶瓷在1100℃下烧结1小时的压电常数d33，机电耦合系数Kp，相对介电常数r，介电损耗tanδ分别为216pC/N，0.49，1980和0.0356。
尝试了PLZT低温烧结陶瓷在制备铁电/铁磁复合陶瓷中的应用。采用共烧工艺制备了质量比为1:9、2:8、3:7和4:6的铁酸钴CFO/PLZT磁电复合陶瓷。X-射线分析结果表明：该复合物中CFO和PLZT两相共存，相界清晰，无杂相产生。1100℃下烧结的CFO/PLZT质量比为2:8样品的密度、压电常数d33和机电耦合系数Kp分别为6.51g/cm3、23.8pC/N和0.083。
关键词：锆钛酸铅镧陶瓷；低温烧结；氟化物；磁电复合材料；铁酸钴
Abstract:The lead lanthanum zirconate titanate Pb0.91La0.06(Zr0.58Ti0.42)0.975Nb0.02O3(PLZT) powders were coated with LiF and PbF2 via a chemical deposition method. Using the LiF and PbF2 (molar ratio 1:1, PLF) as sintering additives, the piezoelectric ceramics (PLZT) were fabricated via conventional solid sintering method. The effects of PLF content and sintering conditions on the phase structure, micro-morphology, dielectric, piezoelectric and ferroelectric properties were investigated. The PLF modified PLZT ceramics present a perovskite structure. The grains show a uniform size. The PLZT ceramics doped with 6-8 wt% PLF can be obtained at the sintering temperature of 1000-1100°C. The glass materials could be absorbed in the main crystalline phase at higher sintering temperature. The piezoelectric constant, electromechanical coupling coefficient, dielectric permittivity and dielectric loss of PLZT with 6wt.% PLF content sintered at 1100℃ for 1 hour were found to be 216 pC/N, 0.49, 1980 and 0.0356, respectively.
It was tried to use PLF modified PLZT for fabricating ferroelectric/ferromagnetic composites. The CFO/PLZT composite ceramics with mass ratio of 1:9, 2:8, 3:7 and 4:6 were prepared using co-firing method. The X-ray diffraction patterns showed that two separate CFO and PLZT phases were existed, phase boundaries were clear and almost no other phase were found. The density, piezoelectric constant and electromechanical coupling coefficient of the CFO/PLZT with mass ratio of 2:8 sintered at 1100℃ were found to be 6.51g/cm3, 23.8pC/N and 0.083, respectively.
Keywords: PLZT; low-temperature sintering; fluoride ; magneto-electric materials; cobalt ferrite
