Multilevel recording in Ge$_{2}$Sb$_{2}$Te$_{5}$ thin films

The current–voltage characteristics measured on Ge$_{2}$Sb$_{2}$Te$_{5}$ thin films in the current mode are studied. The effect of multilevel recording is established when applying sequential current pulses with increasing maxima. It is shown that this effect can be associated with memory-channel expansion. The memory-channel size is estimated. It is concluded that Ge$_{2}$Sb$_{2}$Te$_{5}$ films can be used as memristors.