The pulse‐degradation characteristic of ZnO varistors
The pulse‐degradation characteristic of ZnO varistors
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DOI：
10.1063/1.326719
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发表时间：
1979-09
影响因子：
3.2
通讯作者：
C. Shirley;W. Paulson
中科院分区：
文献类型：
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作者：
C. Shirley;W. Paulson
我们发现有两个因素会影响压敏电阻电子特性的高能脉冲退化。首先，活性晶界部分的电子结构仅取决于脉冲期间出现的峰值温度，其次，该峰值温度由微观结构的热传输特性决定。我们发现，通过在氧气中低温（600°C）退火，可以在不改变微观结构的情况下修改固有电子结构，从而大大提高压敏电阻的脉冲降解性能。微观结构的影响体现在晶界温度放大系数Zgb中，它是定义、测量和理论研究的。理论表明存在三种状态：（i）长脉冲宽度状态，其中Zgb=1，（ii）短脉冲宽度状态，其中Zgb∼（脉冲宽度）−1/2，与脉冲能量无关，以及（iii）极短脉冲宽度（或高能量密度）状态，其中Zgb∼（脉冲能量）−1/2，独立于...
We find that two factors bear on the high‐energy pulse degradation of a varistor’s electronic characteristic. First, the electronic structure of active grain‐boundary segments depends solely on the peak temperature occurring there during a pulse, and second, this peak temperature is determined by the thermal transport properties of the microstructure. We find that the intrinsic electronic structure can be modified without changing the microstructure to greatly improve the pulse‐degradation performance of a varistor by an anneal at low temperature (600 °C) in oxygen. The influence of microstructure is embodied in the grain‐boundary temperature‐magnification factor Zgb which is defined, measured, and studied theoretically. Theory shows that there are three regimes: (i) a long‐pulse‐width regime where Zgb=1, (ii) a short‐pulse‐width regime where Zgb∼ (pulse width)−1/2, independent of pulse energy, and (iii) a very‐short‐pulse‐width (or high‐energy‐density) regime where Zgb∼ (pulse energy)−1/2, independent of...