The non-Arrhenius behaviour of Ge₂Sb₂Te₅ conductivity is attributed to the non-linear temperature dependence of the Fermi level, assuming extended state conduction by free holes. The temperature-dependent Fermi level is shown to alter values of activation energy and prefactor for conductivity so that their exact determination becomes impossible using the conductivity data alone. However, if one assumes the temperature dependence of the Fermi level to be a parabolic function. Then, two of three model parameters can be retrieved; to obtain the third parameter one has to make an assumption about the value of prefactor for conductivity. Applying the proposed analysis scheme to Ge₂Sb₂Te₅, reasonable values of Fermi level position are obtained and the change of Fermi level as a result of resistance drift phenomenon is demonstrated.

Ge ₂ Sb ₂ Te ₅导电性的非阿伦尼乌斯行为归因于费米能级的非线性温度依赖性，假设自由空穴的扩展态传导。与温度有关的费米能级显示会改变活化能值和电导率前因子，因此仅使用电导率数据无法准确确定它们。然而，如果假设费米能级的温度依赖性是抛物线函数。然后，可以检索三个模型参数中的两个；为了获得第三个参数，必须对电导率前因子的值进行假设。将建议的分析方案应用于 Ge ₂ Sb ₂ Te ₅，获得了合理的费米能级位置值，并证明了由于电阻漂移现象导致的费米能级变化。