Characteristics of different types of filaments in resistive switching memories investigated by complex impedance spectroscopy.

Complex impedance spectra of the low- and high-resistance states of Au/NiO/Pt and ITO/TiO2/ITO heterostructures were studied to probe the characteristics of conducting filaments (CFs). Different types of CFs were compared both qualitatively and quantitatively. It was demonstrated that important information of CFs, including the conducting behavior as well as the position and degree of rupture, can be obtained by analysis of the complex impedance data. We further employed this tool to explore resistive switching effect in HfO2 based heterostructures fabricated by different methods, and revealed the switching mechanisms and the effect of growth process on the properties of CFs. [ABSTRACT FROM AUTHOR]