  Electrical characteristics of a Co/TiO_x/Co resistive memory device,
fabricated by two different methods are reported. In addition to crystalline
TiO_2 layers fabricated via conventional atomic layer deposition (ALD), an
alternative method has been examined, where TiO_x nanoparticle layers were
fabricated via sol-gel. The different devices have shown different hysteresis
loops with a unique crossing point for the sol-gel devices. A simple
qualitative model is introduced to describe the different current-voltage
behaviours by suggesting only one active metal-oxide interface for the ALD
devices and two active metal-oxide interfaces for the sol-gel devices.
Furthermore, we show that the resistive switching behaviour could be easily
tuned by proper interface engineering and that despite having a similar active
material, different fabrication methods can lead to dissimilar resistive
switching properties.
