传感器电解质材料热膨胀性能和热稳定性变化规律研究

Research on thermal expansion performance and thermal stability of sensor electrolyte material

以ZrO2固体电解质材料为例,研究氧传感器电解质材料原子振动特点和热膨胀系数及其热稳定性随温度和时间的变化规律,探讨原子非简谐振动的影响.结果表明:原子振动的频率、阻尼系数,在简谐近似下为常数,在考虑到非简谐效应后随温度升高而增大;原子平均位移和热膨胀系数在简谐近似下为零,在考虑到非简谐效应后随温度升高而增大,随时间的增长而减小;热膨胀性能稳定性温度系数随温度的升高而减小,随时间的增长而增大,即使用时间越长,材料的热膨胀性能稳定性越低;温度越高,热膨胀性能越稳定;非简谐情况下的原子振动的频率、阻尼系数和热膨胀系数与简谐近似下的差值随温度的升高而增大,即温度越高,非简谐效应越显著.

Taking the ZrO2 solid electrolyte material as an example,the atomic vibration characteristics,thermal expansion coefficient and thermal stability of the oxygen sensor electrolyte material and the variation of thermal stability with temperature and time are studied.Especially,the influence of atomic anharmonic vibration is discussed.The study indicates that the frequency and damping coefficient of atomic vibration are constants under harmonic approximation,but increase with increasing temperature when taking anharmonic effect into account.The average displacement and thermal expansion coefficient of atom are zero under harmonic approximation,while taking anharmonic effect into account,it increases with increasing temperature,and decreases with time.The temperature coefficient of thermal expansion performance stability decreases with increasing temperature,and increases with time,that is,the longer used time the material,the worse the stability of thermal expansion performance.The higher the temperature,the more stable the thermal expansion performance.The differences of the frequency,damping coefficient and thermal expansion coefficient of atomic vibration between the anharmonic and harmonic approximations increase with the increasing temperature,that is,the higher the temperature,the more significant the anharmonic effect.