Li改性铌钽酸钾钠无铅压电陶瓷的研究

Li-modified Sodium Potassium Tantalum Niobate Lead-free Piezoelectric Ceramics

利用固相反应法制备了(Na0．52K0．48-xLix)(Nb0.86Ta0.10Sb0．04)O3系无铅压电陶瓷,研究了不同Li含量(x分别为0、0．02、0．04、0．06、0．08)样品的显微结构、物相组成及电性能．结果表明,Li含量的改变对其物相组成、压电性能、铁电性能、介电性能都有显著影响．当Li含量x从0增大到0．04时,其压电性能相应提高,当Li含量x超过0．04时,压电性能明显下降;在x=0．04时综合性能最好,其压电常数d33高达260pC／N,介电损耗tanδ为0．027,平面机电耦合系数kp值达到50％,剩余极化强度Pr为22μC·cm-2,矫顽电场Ec为0．95kV·mm-1,居里温度为316℃．另外,随着Li含量增加,该系统的矫顽电场明显增强,居里温度有所提高．

Lead-free piezoelectric （Na0.52K0.48-xLix）（Nb0.86Ta0.10Sb0.04）O3 ceramics were prepared by solid state reaction. The microstructure, phase and electric properties were studied for （Na0.52K0.48-xLix） （Nb0.s6Ta0.10Sb0.04）O3 samples with different Li content （x being 0, 0.02, 0.04, 0.06, 0.08）. Results show that their phases, piezoelectric, dielectric and ferroelectric properties of （Na0.52 K0.48-xLix） （Nb0.s6 Tao.10- Sb0.04）O3 lead-free ceramics are much influenced by the content of Li ions. The piezoelectric properties are enhanced when Li content increases from 0 to 0.04, and decreased when Li content （x） is more than 0.04. Best electric properties are obtained for the sample when x equals 0.04, with its piezoelectric constant d33 being 260pC/N, dielectric loss tan5 being 0.027, planar coupling factor kp being 50%, remanent polarization Pr being 22μC·cm^-2, coercive electric field Ec being 0.95kV·mm^-1, Curie temperature being 316μ. With the increase of Li content, the coercive electric field Ee increases obviously, and the Curie temperature is also enhanced.