Probe microscopy of resistive switching in nanocrystalline copper oxide (Cu$_x$O)

The paper studies the effect of resistive switching in nanocrystalline copper oxide (Cu$_x$O) films synthesized by vacuum arc deposition in an argon-oxygen atmosphere. The structural and electrophysical properties of films with different phase compositions (Cu$_2$O, CuO, mixed phases) are studied using X-ray diffraction, Raman and photoluminescence spectroscopy, and atomic force microscopy. It is found that changing the partial pressure of oxygen during synthesis allows one to control the stoichiometry and defect structure of oxides. Conductive atomic force microscopy modes are used for local analysis of resistive switching, demonstrating bipolar behavior for mixed Cu$_x$O phases. The results confirm the promise of nanocrystalline copper oxides for creating memristors with controlled characteristics.