Current-voltage characteristics of thin Ge$_2$Sb$_2$Te$_5$ films taken using a measuring circuit with a current source

The measuring circuit with a voltage generator, which is traditionally used for studying electric properties of glasslike semiconductors, is compared with an alternative version using a current generator. The results obtained in the latter case reflect the interrelation between the memory formation effect and changes in the electrical parameters more comprehensively. A new electric parameter, viz. hold voltage $U_{\mathrm{hold}}$, which has not been described earlier, is introduced. The relation between $U_{\mathrm{hold}}$ and the memory formation process during the phase transition is established. The effect of emergence of oscillations in the current-limiting regime in the conduction channel in the film is detected.