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DS: Fachverband Dünne Schichten

DS 13: Phase Change/Resistive Switching

DS 13.5: Vortrag

Montag, 20. März 2017, 16:00–16:15, CHE 91

Investigation of oxygen vacancy formation and migration in HfO₂ from density functional theory — •Marta Gibertini, Daniel Wortmann, Gustav Bihlmayer, Shigeru Tsukamoto, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany

Among the investigated storage devices, resistive random access memory (ReRAMs) are currently considered relevant because of the high-speed/high-density properties and the low energy required for the writing/rewriting cycles. A deeper understanding of the role played by point defects and dopants in the used materials is important for an optimization of those devices.

We present a density functional theory (DFT) study aimed at the investigation of the formation energies and the migration energy barriers of oxygen vacancies in Y-doped and undoped monoclinic HfO₂. We look at these properties in bulk and film systems where the formation energy is calculated also at the surface, and the dependence on the magnitude of an external electric field is studied. The nudged elastic method is applied and the DFT calculations are performed with the electronic structure code jüRS, a real-space finite-difference implementation of the projector augmented wave (PAW) method. The real-space formalism is chosen because it allows a flexible treatment of the boundary conditions and therefore it is favorable for the implementation of an external electric field. – Work is supported by DFG - SFB 917 (Nanoswitches).