Magneto-ionics is an emerging field that offers great potential for reducing power consumption in spintronics memory applications. By combining the concept of voltage-controlled ionic motion from memristor technologies, typically used in neuromorphic applications, with spintronics, this field also provides a unique opportunity to create a new generation of neuromorphic functionalities based on spintronics devices. The main objective of the internship was to investigate the dynamics of 90° domain walls between two anisotropy states, a new promising spin structure, under the application of a gate voltage in oxygen-based magneto-ionic devices in order to design artificial synaptic functionalities. This was accomplished through the combination of magneto-transport measurements and Kerr microscopy magnetic imaging.