Bulk and grain boundary resistivities as well as grain boundary capacitances of PTCR (positive temperature coefficient of resistivity) thermistors have been investigated as a function of voltage load and temperature ranging from 30 to 820 °C by application of impedance spectroscopy. In addition, current – voltage curves have been measured and the resistivities extracted from these dc measurements are in close agreement with those obtained from impedance spectroscopy. The resistance – temperature characteristics are typical for n-type barium titanate – based PTCR ceramics, viz. a steep increase of the grain boundary resistance above the Curie – temperature (PTCR effect) and decreasing resistance with increasing temperature in the NTC (negative temperature coefficient) regime above approximately 200 °C. The grain boundary capacitance shows a sharp peak at the Curie – temperature (around 120 °C) and obeys the Curie – Weiss law in the paraelectric state. Basically, the grain boundary resistivities decrease significantly under voltage load. However, at elevated temperatures (above 600–700 °C) this non-linear effect vanishes and linear ohmic (or even sub-ohmic) behavior can be observed. The electrical properties can be interpreted in terms of a modified double Schottky barrier model. Reasonable coincidence between simulated and measured current - voltage curves as well as grain boundary conductivities has been found in a wide temperature range (up to 800 °C) under high field conditions (up to an external field strength of 1000 V cm⁻¹).

PTCR热敏电阻的体积和晶界电阻率以及晶界电容（电阻率正温度系数）已经通过阻抗谱研究了电压负载和温度范围为30至820°C的函数。另外，已经测量了电流-电压曲线，并且从这些直流测量中提取的电阻率与从阻抗谱获得的电阻率非常一致。电阻-温度特性是n型钛酸钡基PTCR陶瓷的典型特性。在高于居里温度（PTCR效应）时，晶界电阻急剧增加，在大约200°C以上的NTC（负温度系数）状态下，随着温度的升高电阻降低。晶界电容在居里温度（约120°C）处显示一个尖峰，并在顺电状态下遵守居里-魏斯定律。基本上，在电压负载下，晶界电阻率显着降低。但是，在高温（高于600–700°C）下，这种非线性效应消失了，可以观察到线性欧姆（甚至亚欧姆）行为。可以根据修正的双肖特基势垒模型来解释电性能。在宽的温度范围（高达800°C）和高场条件下（高达1000 V cm的外部场强），发现模拟和测量的电流-电压曲线以及晶界电导率之间存在合理的重合性 在电压负荷下，晶界电阻率明显降低。但是，在高温（高于600–700°C）下，这种非线性效应消失了，可以观察到线性欧姆（甚至亚欧姆）行为。可以根据修正的双肖特基势垒模型来解释电性能。在宽的温度范围（高达800°C）和高场条件下（高达1000 V cm的外部场强），发现模拟和测量的电流-电压曲线以及晶界电导率之间存在合理的重合性 在电压负荷下，晶界电阻率明显降低。但是，在高温（高于600–700°C）下，这种非线性效应消失了，可以观察到线性欧姆（甚至亚欧姆）行为。可以根据修正的双肖特基势垒模型来解释电性能。在宽的温度范围（高达800°C）和高场条件下（高达1000 V cm的外部场强），发现模拟和测量的电流-电压曲线以及晶界电导率之间存在合理的重合性 可以根据修正的双肖特基势垒模型来解释电性能。在宽的温度范围（高达800°C）和高场条件下（高达1000 V cm的外部场强），发现模拟和测量的电流-电压曲线以及晶界电导率之间存在合理的重合性 可以根据修正的双肖特基势垒模型来解释电性能。在宽的温度范围（高达800°C）和高场条件下（高达1000 V cm的外部场强），发现模拟和测量的电流-电压曲线以及晶界电导率之间存在合理的重合性^-1）。