Influences of Ba/Ti Ratios on the Positive Temperature Coefficient of Resistivity Effect of Y‐Doped BaTiO3–(Bi1/2Na1/2)TiO3 Ceramics
Influences of Ba/Ti Ratios on the Positive Temperature Coefficient of Resistivity Effect of Y‐Doped BaTiO3–(Bi1/2Na1/2)TiO3 Ceramics
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DOI：
10.1111/j.1551-2916.2011.04506.x
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发表时间：
2011-05
影响因子：
3.9
通讯作者：
S. Leng;Guorong Li;Liaoying Zheng;Lihong Cheng;Jiangtao Zeng
中科院分区：
文献类型：
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作者：
S. Leng;Guorong Li;Liaoying Zheng;Lihong Cheng;Jiangtao Zeng
采用常规固相烧结法制备了y掺杂（1−x mol%） BaTiO3-x mol%(Bi1/2Na1/2)TiO3 （BBNTx）无铅正温度电阻率（PTCR）陶瓷。调整Ba/Ti比，得到优化的PTCR性能。结果表明：不同Ba/Ti比掺杂0.2 mol% y的BBNT15样品在N2气氛中烧结形成了单一的四方钙钛矿相；含5mol % (Bi1/2Na1/2)TiO3的样品在N2中烧结时，PTCR效应（最大电阻率[ρmax]/最小电阻率[ρmin]）较小。然而，当（Bi1/2Na1/2）TiO3含量为bbb8 mol%时，PTCR效应增强超过3.0个数量级。过量Ti样品的PTCR特性优于过量Ba样品。在1250℃的N2气氛中烧结3h，得到了掺y量为0.2 mol%、Ba/Ti=0.99的BBNT15的最佳组成，其室温电阻率（ρ25）为~ 100 Ω·cm，在190℃左右的温度下，PTCR效应高达~ 4.8个数量级。
Y-doped (1−x mol%)BaTiO3–x mol%(Bi1/2Na1/2)TiO3 (BBNTx) lead-free positive temperature coefficient of resistivity (PTCR) ceramics were prepared using a conventional solid sintering method. The Ba/Ti ratio was adjusted to obtain the optimized PTCR property. The results show that all 0.2 mol% Y-doped BBNT15 samples with various Ba/Ti ratios have formed a single tetragonal perovskite phase by sintering in an N2 atmosphere. The sample with 5 mol% (Bi1/2Na1/2)TiO3 has only a minor PTCR effect (maximum resistivity [ρmax]/minimum resistivity [ρmin]) when sintered in N2. However, the PTCR effect is enhanced over 3.0 orders of magnitude when the (Bi1/2Na1/2)TiO3 content is >8 mol%. The PTCR characteristics of the samples with Ti excess are superior to those with Ba excess. The optimum composition of 0.2 mol% Y-doped BBNT15 with Ba/Ti=0.99, sintered at 1250°C for 3 h in an N2 atmosphere, has a low room-temperature resistivity (ρ25) of ∼100 Ω·cm and a high PTCR effect of ∼4.8 orders of magnitude with Tc around 190°C.