锂离子掺杂量对BLMNS陶瓷的介电性能的影响

采用传统固相法制备Bi2-xLix(Mg1/3Nb0.517Sn0.15)2O7(BLMNS)(x=0.025,0.05,0.075,0.1mol)陶瓷,利用X射线衍射、扫描电镜等测试分析方法系统研究锂离子掺杂对BLMNS陶瓷的介电性能和结构的影响。结果表明:在所掺杂锂离子的陶瓷中仍保持单一的单斜焦绿石相结构,无第二相出现。随着锂离子取代量的增加,陶瓷的晶粒尺寸变化不大,晶粒尺寸稍有增大,介电常数(εr)先减小后增大,介电损耗(tanδ)先减小后增大,陶瓷的密度一直减小。随着烧结温度增加,陶瓷的密度先增大后减小。烧结温度为980℃时,锂离子掺杂的BLMNS陶瓷的密度最大。在980℃烧结时锂离子取代量为0.05mol时BLMNS陶瓷的性能较好:εr=163(1MHz),tanδ=0.0001(1MHz),体积密度为7.55g/cm3。     

Influence of CeO2 doping amount on property of BCTZ lead-free piezoelectric ceramics sintered at low temperature

Ba0.85Ca0.15Ti0.9Zr0.1O3(BCTZ) lead-free piezoelectric ceramics co-doped with CeO2(x=0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%) and Li2CO3(0.6 wt.%) were prepared by conventional solid-state reaction method. Influence of CeO2 doping amount on the piezoelectric properties, dielectric properties, phase composition and microstructure of prepared BCTZ lead-free piezoelectric ceramics doped with Li2CO3 were investigated by X-ray diffraction(XRD) and scanning electron microscopy(SEM) and other analytical methods. The results showed that the sintered temperature of BCTZ lead-free piezoelectric ceramics doped with CeO2 decreased greatly when Li2CO3 doping amount was 0.6 wt.%; a pure perovskite structure of BCTZ lead-free piezoelectric ceramics co-doped with Li2CO3 and CeO2 and sintered at 1050 °C could also be obtained. The piezoelectric constant(d33), the relative permittivity(εr) and the planar electromechanical coupling factor(kp) of BCTZ ceramics doped with Li2CO3 increased firstly and then decreased, the dielectric loss(tanδ) decreased firstly and then increased and decreased at last when CeO2 doping amount increased. The influence of CeO2 doping on the properties of BCTZ lead-free piezoelectric ceramics doped with Li2CO3 were caused by "soft effect" and "hard effect" piezoelectric additive and causing lattice distortion. When CeO2 doping amount(x) was 0.2 wt.%, the BCTZ ceramics doped with Li2CO3(0.6 wt.%) and sintered at 1050 °C possessed the best piezoelectric property and dielectric property with d33 of 436 pC/N, kp of 48.3%, εr of 3650, tanδ of 1.5%.     

分析ZnO压敏电阻器漏电流爬坡现象的影响因素及其解决措施

分析了实际生产中对ＺｎＯ压敏电阻器的漏电流爬坡产生影响的主要因素,提出了解决漏电流爬坡的措施,为ＺｎＯ压敏电阻器的生产提供了一定的理论依据。     

CaTiO_3掺杂对BST铁电电容器陶瓷性能的影响

采用固相法制备了CaTiO3掺杂的(Ba0.65Sr0.35)TiO3(BST)陶瓷,研究了CaTiO3掺杂量对BST电容器陶瓷介电性能和微观结构的影响。结果表明:随着CaTiO3掺杂量的增加,BST陶瓷的相对介电常数(εr)先增大然后减小然后增大,介质损耗(tanδ)和交流耐压强度(Eb)先增大然后减小。当CaTiO3掺杂量为摩尔分数10%时,BST陶瓷的综合介电性能较好:εr为4480,tanδ为0.022,Eb为5.8×103V/mm(AC),容温特性符合Y5U特性。     

纳米TiO_2半导体催化活性的研究进展

纳米TiO2半导体催化技术具有广阔的应用前景,近年来半导体光催化已成为功能陶瓷材料、光化学、环境保护、生物技术等领域的研究热点之一。本文简要介绍了近年来国内外纳米TiO2半导体光催化剂的研究进展,主要包括纳米TiO2光催化剂的作用机理及结构的影响;提高催化活性的方法,指出了表面贵金属沉积、复合半导体、金属离子掺杂和表面光敏化是提高催化活性和催化效率的有效途径。     

Study on Ferroelectric and Dielectric Properties of La-Doped CaBi4Ti4O15-Based Ceramics

Research on bismuthlayer structuredferroelectricceramics as piezoelectric material with high Curie tem-perature ,strong anisotropic characters ,lowdielectricdissipationfactor and lowaging rate has attracted in-creasing interest[1,2].It can be used to manu…     

二氧化锡透明导电薄膜的研究进展

透明导电薄膜具有透明性和导电性,在平板显示器、太阳能电池、触摸屏等领域有着重要的作用。SnO_2是制备透明导电薄膜最具潜力的材料之一。结合国内外SnO_2透明导电薄膜的研究现状,主要对SnO_2薄膜的透明导电原理、制备方法和掺杂改性研究进展进行综述。     

烧结温度对大功率超薄型压电蜂鸣器用压电陶瓷结构和性能的影响

采用轧膜成型工艺制备大功率超薄型峰鸣器用压电陶瓷。该陶瓷是三方／四方相共存PSN—PBZT(0．02Pb(Sb0．5Nb0．5)O3—0．98PbxBa1-z(Zr0.55Ti0.45)O3)压电陶瓷。研究了烧结温度对三方／四方相共存PSN—PBZTB陶瓷性能的影响，利用XRD和SEM研究了烧结温度对其结构的影响。结果表明，随着烧结温度的升高，材料的晶格常数轴率比Ct／at逐渐升高，ar有所降低，同时，材料的晶粒尺才增大，材料的介电常数和机电耦合系数增大。但是，烧结温度太高将手致其介电常数和机电耦合系数降低，这是由于出现玻璃相和游离氧化锆稀释铁电相所致。     

稀土氧化物在（Ba,Sr）TiO3基陶瓷材料中的应用

综述了稀土氧化物在各种作用的（Ba,Sr)TiO3基陶瓷中的掺杂改性和应用现状，详细讨论了稀土氧化物掺骠改性作用机理，分析了该领域应用研究的发展方向。为稀土氧化物掺杂改性（Ba,Sr)TiO3基陶瓷提供理论依据。