【作者】 谭焕银；

【导师】 孙清池；

【作者基本信息】 天津大学 ， 材料学， 2007， 硕士

【摘要】 本实验Pb_1.02(Mn_1/3Sb_2/3)_0.05(Ni_2/3W_1/3)_x(Zr_0.495Ti_0.505)_0.95-xO₃（PMS-PNW-PZT）四元系压电陶瓷材料是由传统固相法制备的,通过X射线衍射（XRD）对合成后材料的晶相进行了分析,用扫描电子显微镜（SEM）观察了样品表面的显微结构,并且讨论了组成和烧结温度对材料介电、压电性能及稳定性影响。通过研究不同镍钨掺杂对PMS-PNW-PZT系统性能的影响发现:三方相和四方相共存的准同型相界（MPB）是一个很宽的组成范围;在850℃煅烧,1090℃烧结保温2h时,当x=0.01时,得到综合性能优良的压电材料:相对介电常数ε^T₃₃/ε₀= 1560,介电损耗tanδ=0.5%,压电常数d₃₃=360pC/N、d₃₁=160 pC/N,机电耦合系数K_p =66.5%、K₃₁=40.5%,机械品质因数Q_m=1900,居里温度T_c=287℃;随着NiW含量的增加,四方相向三方相转变,降低了居里温度且增大了弥散程度。此外,还研究了不同镍钨含量掺杂对PMS-PNW-PZT四元系统机电性能的稳定性影响。谐振频率的温度系数由正变为负,在x=0.01时获得最小值(TKfr=1.01×10^-4/℃),反映了四方相向三方相的转变。此时TCK₃₁=0.030%/℃,TCd₃₁=0.021%/℃相比其他组分数值也是最小的,说明x=0.01时材料的温度稳定性得到了很大的提高。850℃煅烧、1090℃烧结且保温2h的条件下,在经时老化过程中,0.05PMS–0.01PNW–0.94PZT体系陶瓷的介电、压电性能如下变化:相对介电系数ε^T₃₃/ε₀下降,谐振频率f_r上升;机电耦合系数K_p下降,机械品质因数Q_m上升,并且最终都达到一个稳定值。0.05PMS–0.01PNW–0.94PZT体系的AK_p=-0.068,Ad₃₁=-0.053, Atanδ=-0.24,这些参数的老化率的绝对值相比其他组分是最小的,这说明机电性较好的x=0.01的样品的老化稳定性得到很大改善。0.05PMS–0.01PNW–0.94PZT体系陶瓷介电和压电性能在100℃时与老化时间的对数呈线性关系,而在150℃时与老化时间的对数呈指数延伸规律。PMS–PNW–PZT体系陶瓷最佳烧结温度（1090℃）与锑锰锆钛酸铅（PMSZT）体系的最佳烧结温度（1240℃）相比,说明镍钨共掺杂作为助熔剂起到了低温烧结的作用。更多还原

【Abstract】 Pb_1.02(Mn_1/3Sb_2/3)_0.05(Ni_2/3W_1/3)_x(Zr_0.495Ti_0.505)_0.95-xO₃（PMS-PNW-PZT）quaternary piezoelectric ceramics were prepared by conventional solid solution method. The X-ray diffraction （XRD） and the scanning electronic microscope （SEM） were applied to analyze phases and microstructure, respectively. The effects of the composition and the sintering temperature on the dielectric and piezoelectric properties and temperature stability of the system were also discussed. The study on the properties of the system doped by NiW indicated that the MPB of the tetragonal and rhombohedral phase lay in a broad composition region. The optimum properties were obtained with x=0.01at calcination temperature of 850℃and sintering temperature of 1090℃. The main parameters:ε₃₃^T/ε₀=1560, tanδ=0.5%, d₃₃=360pC/N, K_p =66.5%, Q_m=1900, T_c=287℃. Partial substitution of NiW for TiZr shifted compositions away from the tetragonal phase across the MPB toward the rhombohedral phase, greatly reduing the Curie temperature and broadening the dielectric constant maximum.In addition, The temperature coefficient of resonant frequency shifted from plus （+） into minus （-） value with increasing NiW ratio and obtained a minimum value (TKfr=1.01×10^-4/℃) at x=0.01, which reflected the transition from tetragonal phase to rhombohedral phase. The addition of NiW greatly enhanced the temperature stability of PMS–PNW–PZT system and the temperature coefficient of resonant frequency （TKfr） in the range of -25⁸0℃. When calcination temperature is 850℃and sintering temperature is 1090℃, the optimum aging properties of PMS–PNW–PZT quaternary system were obtained with x=0.01. When the temperature of aging is 100℃, aging behaviors of piezoelectric and dielectric constant follow the linear logarithmic time law,which follow the stretched exponential law with the logarithmic time while the temperature of aging is 150℃.The optimum sintering temperature（1090℃） of PMS–PNW–PZT system compared with the PMSZT system（1240℃）,which showed that NiW as function of fiuxing agent play an important part to low sintering temperature.更多还原