Synthesis of Y‐Doped BaTiO3–(Bi1/2K1/2)TiO3 Lead‐Free Positive Temperature Coefficient of Resistivity Ceramics and Their PTC Effects
Synthesis of Y‐Doped BaTiO3–(Bi1/2K1/2)TiO3 Lead‐Free Positive Temperature Coefficient of Resistivity Ceramics and Their PTC Effects
复制标题
DOI：
10.1111/j.1551-2916.2009.03251.x
复制
发表时间：
2009-11
影响因子：
3.9
通讯作者：
S. Leng;Guorong Li;Liaoying Zheng;Tianbao Wang;Q. Yin
中科院分区：
文献类型：
--
作者：
S. Leng;Guorong Li;Liaoying Zheng;Tianbao Wang;Q. Yin
采用传统的固相反应法制备了(1-x摩尔%)BaTiO_3-x摩尔%(Bi1/2K1/2)TiO_3-y摩尔%Y_2O_3-0.5摩尔%TiO_2(BT-xBKT-2yY-0.5TiO_2)系无铅正电阻温度系数材料。在空气中烧结的样品具有较低的室温电阻率(ρ25)和较高的正温度系数(PTC)效应。然而，当BKT含量超过2mol%时，样品在空气中烧结后不是半导化的。讨论了烧成制度对PTCR陶瓷性能的影响。结果表明，最佳配方为BT-1BKT-0.2Y-0.5TiO21330℃不浸渍，然后在空气中快速淬火，可获得较低的ρ_(25)为28Ω·cm，最大电阻率[PTC_(Max)/最小电阻率[PTC_(Min)])跳跃为4个数量级，T_c约为155°C。在氮气中于450℃保温30min，可使烧结样品的ρ_(25)进一步降低到10Ω·cm左右，并伴随着PTC效应的降低。
As a lead-free positive temperature coefficient of resistivity (PTCR) material, (1–x mol%) BaTiO3–x mol% (Bi1/2K1/2) TiO3–y mol% Y2O3–0.5 mol% TiO2 (BT–xBKT–2yY–0.5TiO2) systems were prepared by the conventional solid-state reaction method. All samples containing <2 mol% BKT sintered in air possessed relatively low room-temperature resistivity (ρ25) and high positive temperature coefficient (PTC) effect. However, when the BKT content exceeded 2 mol%, the sample was not semiconductive after sintering in air. The effects of sintering schedule on the properties of PTCR ceramics were discussed. The results showed that the optimum composition of BT–1BKT–0.2Y–0.5TiO2, sintered at 1330°C for not-soaking and then fast quenched in air, achieved rather low ρ25 of 28 Ω·cm and a high jump of resistivity (maximum resistivity [ρmax]/minimum resistivity [ρmin]) of 4.0 orders of magnitude with Tc about 155°C. The ρ25 of the as-sintered sample could be further reduced to about 10 Ω·cm by annealing in N2 at 450°C for 30 min, accompanied decrease on the PTC effect.