the resistivity of metal oxide (thermistor)
Why should the resistivity of metal oxide be dependent on the temperature?
- 匿名1 十年前最愛解答
Electrical conductivity is strongly dependent on temperature. In metals, electrical conductivity decreases with increasing temperature. Metals conduct electricity so well because they contain free electrons that move through a lattice of positive ions. At higher temperature the protons start vibrating and moving slightly out of position. As their motion becomes more erratic they are more likely to get in the way and disrupt the flow of the electrons. Thus the higher the temperature, the higher the resistance. Since the relationship of temperature and resistivity (or conductivity, its reciprocal) in metals are quite linear in wide temperature range, their oxide form are mostly used in PTC (Positive Temperature Coefficient) thermistors. The metal oxide has much higher resistivity and much more stable than in metal form.
In fact the resistivity of all matters are dependent on temperature, while metals or metal oxides has the most linear relationship with temperature.