Sb2O3对ZnO基陶瓷性能的影响

本文主要报道Ｓｂ２Ｏ３杂质对ＺｎＯ基陶瓷性能的影响。在ＺｎＯ基陶瓷中添加Ｓｂ２Ｏ３杂质可以改善此种瓷的压敏性和介电性。     

退火过程中Ti4+离子对低压ZnO陶瓷压敏性能的影响

本文对烧成后的掺ＴｉＯ２低压ＺｎＯ压敏陶瓷进行了退火处理。测量了不同退火温度下ＺｎＯ陶瓷的压敏性能,运用ＸＲＤ,ＳＥＭ等分析方法研究了退火过程中ＺｎＯ陶瓷结构的变化。研究结果表明,退火过程中Ｔｉ＾４＋离子取代Ｚｎ＾２＋离子而固溶进入ＺｎＯ晶粒表面,是引起ＺｎＯ陶瓷压敏性能变化的主要原因,在退火温度不超过４００℃时可获得较好的压敏性能。     

氧化锌压敏材料研究与发展进展

本文简要回顾了ＺｎＯ压敏陶瓷的历史，阐述了ＺｎＯ压敏陶瓷的特点以及当前ＺｎＯ压敏陶瓷基础性研究的现状，最后对其进展进行了展望。     

Fe0.5Sr0.5CoO3酒敏陶瓷性能的研究

本文通过在Ｆｅ０．５Ｓｒ０．５ＣｏＯ３酒敏陶瓷基体中掺杂不同量的Ｎｂ２Ｏ５、ＣｄＯ、Ｌａ２Ｏ３、ＳｎＯ２等，研究了氧化物掺杂对酒敏陶瓷灵敏度峰值温度的影响。结果表明：这四种掺杂物都能一定程度降低Ｆｅ０．５Ｓｒ０．５ＣｏＯ３酒敏陶瓷的灵敏度峰值温度，且掺杂量为３％（摩尔比）左右时，该陶瓷的敏感度最好。     

ZnO压敏陶瓷的非线性功能添加剂

本文采用单元掺杂与多元掺杂的方法，系统研究了几种过渡金属氧化物添加剂在控制ＺｎＯ压敏陶瓷非线性方面的作用，并根据金属阳离子外壳层电子结构稳定性和缺陷化学反应进行了分析，认为阳离子具有不饱和外层电子结构且半径与Ｚｎ＾２＋离子相近的过渡金属氧化物能改善ＺｎＯ压敏陶瓷非线性。     

中温烧结MgO—TiO2—ZnO系陶瓷结构和性能的研究

本文在研究中温烧结ＭｇＯ－ＴｉＯ－ＺｎＯ系陶瓷基础上，获得了温度系数接近于零的瓷料（ＮＰＯ）。ＸＲＤ证明其主晶相为正钛酸镁（２ＭｇＯ．ＴｉＯ２）还有正钛酸锌（２ＺｎＯ．ＴｉＯ２）和ＣａＴｉＯ３附加晶相，同时研究了各组分的不同含量对介电性能的影响。     

掺杂中温烧结BaTiO_3陶瓷的壳－芯结构与组成、工艺的关系

研究了添加少量Ｎｂ，Ｂｉ，ＣＯ杂质及Ｂ，Ｚｎ玻璃相的ＢａＴｉＯ＿３系陶瓷介电性能与其组成、工艺及结构的关系。发现晶粒壳的Ｋ－Ｔ曲线为单峰，峰值在８０℃左右。陶瓷Ｋ－Ｔ曲线的双峰现象不随Ｎｂ，Ｂｉ添加量的增加而消失，但随Ｃｏ，Ｚｎ添加量增加或烧结温度的提高而向单峰过渡。研究结果表明Ｎｂ，Ｂｉ主要决定壳的成份，Ｃｏ可促进Ｎｂ，Ｂｉ离子向晶粒内部扩散，添加Ｚｎ，Ｃｏ或改变烧结工艺对壳的厚度及成份均有较大影响。     

ZnO压敏陶瓷导电机理的发展与掺杂氧化物的作用

近２０年来，有关ＺｎＯ压敏陶瓷研究方面的报道很多，本文从ＺｎＯ压敏陶瓷的导电机理及掺杂氧化物的作用方面进行了综合评述。     

氧化铟对ZnO压敏陶瓷压敏特性及微观结构的影响

用粒度为０．１－０．３ｍｍ的氧化锌偻末为原料，制得了氧化锌压敏陶瓷片，研究了Ｉｎ２Ｏ３掺杂对其压敏特性和微观结构的影响。结果表明；这种氧化锌粉末具有很高的烧结活性，适合作低压压敏电阻器。     

掺杂中温烧结BaTiO3陶瓷的壳—芯结构与组成,工艺的关系

研究了添加少量Ｎｂ，Ｂｉ，Ｃｏ杂质及Ｂ，Ｚｎ玻璃相的ＢａＴｉＯ３系陶瓷介电性能与其组成、工艺及结构的关系，发现晶粒壳的Ｋ－Ｔ曲线为单峰，峰值在８０℃左右，陶瓷ＫＴ－Ｔ曲线的双峰现象不随Ｎｂ，Ｂｉ添加量的增加而消失，但随Ｃｏ，Ｚｎ添加量增加或烧结温度的提高而向单峰过渡，研究结果表明Ｎｂ，Ｂｉ主要决定壳的成份，Ｃｏ可促进Ｎｂ，Ｂｉ离子向晶粒向部扩散，添加Ｚｎ，Ｃｏ或改变烧结工艺对壳的厚度及成份均有较大     

掺杂对ZnO压敏陶瓷电性能的影响及其应用

ZnO压敏陶瓷具有优良的电流-电压非线性和冲击能量吸收能力、低漏电流和低成本,广泛用于电力系统和电子线路等领域。介绍了掺杂改性对ZnO压敏陶瓷电性能的影响,最后介绍了ZnO压敏陶瓷的应用。     

Sb2O3掺杂对ZnO压敏陶瓷晶界特性和电性能的影响

制备了掺有Sb2O3不同掺杂量ZnO压敏陶瓷样品,采用扫描电镜对样品进行显微结构分析,研究了Sb2O3掺杂浓度对ZnO压缩电阻显微结构和性能的影响,测量了样品的电性能,由样品C－V特性的测量计算出晶界参数,并由此讨论了陶瓷性能与晶界特性的相关性。研究发现,在ZnO压敏陶瓷样品中掺杂适量的Sb2O3可以提高ZnO压敏陶瓷样品的非线性性能,但当Sb2O3的摩尔分数超过0．088％时,电性能反而优化,这是因为Sb2O3掺杂浓度不同会引起晶界势垒高度、施主浓度与陷阱密度的变化,因此Sb2O3掺杂量要控制在适当的范围内。     

Varistor Performance of ZnO-Based Ceramics Related to Their Densification and Structural Development

Electrical potential barriers are often observed in ZnO-based ceramics. Earlier studies on ZnO photoconduction have shown that the narrow regions, where the sintered grains have grown together, control the resistance of the entire sample. In those regions, the surface/volume ratio is sufficiently high for the acceptor concentration (which occurs because of adsorbed oxygen) to exceed the donor concentration inside the ZnO grains. More recent works have shown that Schottky barriers result from interface states because of the chemisorbed oxygen ion at the ZnO-ceramic grain boundaries. The work reported in this paper involves the relationship between the densification of the microstructure and the varistor performance of ZnO ceramics. The emphasis of densification percentage as an indicator of the degree of sintering shows the desirability of continuity across ZnO grain boundaries, without the presence of voids or films of second phases, in optimizing varistor behavior. The effect of oxygen partial pressure on the development of varistor microstructure and electrical properties, as well the kinetics of grain growth, during the sintering process have been determined and are discussed.     

High Nonlinearity and High Voltage Gradient ZnO Varistor Ceramics Tailored by Combining Ga2O3, Al2O3, and Y2O3 Dopants

This paper deals with the electrical characteristics of rare‐earth‐doped ZnO varistor ceramics. Multiple donor dopants (Al³⁺, Ga³⁺, and Y³⁺) were employed to improve the comprehensive performance of ZnO varistor ceramics. The leakage current of rare‐earth‐doped ZnO varistor ceramics decreased noticeably with Ga₂O₃ dopants. The Ga³⁺ dopant occupies the defect sites of grain boundaries and increases the barrier potential of ZnO varistor ceramics, so the leakage current is effectively inhibited. Y₂O₃ is primarily located around the grains, which restrains ZnO grain growth, increasing the voltage gradient. The Al³⁺ goes into the lattices of ZnO grains, decreasing the grain resistance; thus, the residual voltage ratio can be controlled at low levels under a high impulse current. With the combined incorporation of Al³⁺, Ga³⁺, and Y³, excellent electrical properties of ZnO varistor ceramics can be acquired with a nonlinearity coefficient of 87, voltage gradient of 517 V/mm, leakage current of 0.96 μA/cm², and residual voltage ratio of 1.60. These rare multiple donor dopants can aid in engineering high‐quality ZnO varistors.     

石英砂对TiO2压敏陶瓷性能的影响

本文主要研究SiO2对TiO2压敏陶瓷电性能的影响，并对其原因进行了分析.结果表明：通过掺入SiO2可以有效调控TiO2陶瓷的压敏特性，使TiO2压敏陶瓷具有良好的电性能。     

Al-doped ZnO varistors prepared by a two-step doping process

ABSTRACT

It is difficult to dope Al into main grains of ZnO varistor ceramics, especially for small doping amount. Generally, all raw materials including Al dopant are directly mixed together and sintered into ceramics. However, in this direct doping process, Al is apt to stay in grain boundaries, and almost does not enter grains. This does harm to the electrical properties of ZnO varistors. In this paper, we proposed a two-step doping process. Al₂O₃ powder was first mixed only with a part of the ZnO powder and pre-sintered. The pre-sintered powder was mixed with other additives such as Bi₂O₃ and the rest ZnO. Then ZnO varistor ceramics were prepared via solid state sintering processes. Results showed that two-step doped ZnO varistors exhibited improved electrical properties with a significant increased nonlinear coefficient and a great decreased leakage current compared to directly doped ones because more Al was incorporated into ZnO grains.     

A Novel Test Method for Ultrafast Pulse Response Characteristics of ZnO Varistor Ceramics

A ZnO varistors in series connected with a semi‐insulating GaAs photoconductive switches (SI‐GaAs PCSS's), a test method for ultrafast pulse response characteristics of ZnO varistor ceramics with DC bias was presented for the first time. The DC voltage distribution of the PCSS's and the varistors was measured in a dark state and the pulse response characteristics of the ZnO varistor ceramics was examined by a nanosecond laser pulse illuminating the PCSS's. The results indicate that the electric pulse output from the varistors includes capacitive current and conduction current and there is a time delay between their peaks. It is revealed that ZnO varistors has a nonlinear conductivity for the nanosecond electric impulse excitation and the barrier capacitance decay constant of the ceramics sample is 105 ns, which is explained through the analysis of examining the material structure and the conductive mechanisms.     

添加Nd2O3对氧化锌压敏阀片电性能与显微组织的影响

研究了微量Nd2O3添加剂对氧化锌压敏阀片的压敏电位梯度、漏电流和压比的影响,并对其显微组织进行了分析研究,从理论上探讨了Nd2O3对氧化锌压敏阀片电性能与组织的作用机理。研究结果表明:当Nd2O3的摩尔分数为0.04％时,氧化锌压敏阀片的压敏电位梯度最高,漏电流最小,压比最低,具有优良的综合电性能。其原因是Nd2O3加入到氧化锌压敏阀片中,使晶粒尺寸减小所致。     

添加剂对钛酸镁陶瓷性能影响的研究进展

综述了添加剂对钛酸镁陶瓷性能影响的研究现状,烧结及介电性能等方面的进展。研究结果中可以看出,Bi2O3-V2O5、Co2O3、ZnO等氧化物及氧化物玻璃料的添加可以不同程度地大幅降低陶瓷的烧结温度。在Mg2TiO4中掺杂不同添加剂可适当改变其介电常数,满足其介电常数材料的应用需要;在MgTiO3中掺入不同添加剂可不同程度改变其介电常数,得到具有较高Q*f值且τf≈0的钛酸镁基陶瓷材料。从当前研究现状可以看出,掺杂改性是获得所需性能材料的强有力手段,也是今后对钛酸镁基陶瓷性能优化的主要研究方向之一。