Transition metal oxide-based resistor random access memory takes advantage of oxygen-related defects in its principle of operation. Since the change in resistivity of the material was controlled by the oxygen deficiency level, it was of major importance to quantify the kinetics of the oxygen diffusion, key factor for oxide stoichiometry. Ab initio accelerated molecular dynamics techniques were employed to investigate the oxygen diffusivity in amorphous hafnia (HfOx, x = 1.97, 1.0, 0.5). The computed kinetics was in agreement with experimental measurements.

First-Principles Simulation of Oxygen Diffusion in HfOx: Role in the Resistive Switching Mechanism. S.Clima, Y.Y.Chen, R.Degraeve, M.Mees, K.Sankaran, B.Govoreanu, M.Jurczak, S.De Gendt, G.Pourtois: Applied Physics Letters, 2012, 100[13],133102