Strain imaging of a Cu 2S switching device

Strain imaging of electrochemical behavior of a solid electrolyte Cu 2S in switching devices for nonvolatile memories is presented. The precipitation and dissolution of Cu, and the nonstoichiometry changes cause changes in volume. Strain imaging we have proposed detects the volume changes through the surface displacements using scanning probe microscopy and provides high resolution images. We observed the distributions of the electrochemical reactions in Cu 2S and located the Cu bridges causing switching. ► High resolution imaging of electrochemical reactions in a solid electrolyte has been presented. ► Movements of Cu ions in Cu 2S due to electric fields have been imaged with high resolution. ► Individual metal bridge causing large changes in resistance was imaged.