Berlin 2015 – scientific programme

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DS: Fachverband Dünne Schichten

DS 36: Poster Session I

DS 36.20: Poster

Thursday, March 19, 2015, 09:30–12:00, Poster A

Investigation of oxygen vacancies in HfO₂ from density functional theory — •Marta Gibertini, Daniel Wortmann, Andrea Nobile, and Stefan Blügel — Peter Grünberg Institute (PGI-1) and Institute for Advanced Simulation (IAS-1), Forschungszentrum Jülich GmbH and JARA, Jülich, Germany

Study of point defects in materials is important to understand the role that they play in electronic devices such as the resistive random access memory (ReRAMs). The exact mechanism of switching of a ReRAMs between two states: low and high resistance, is unknown, but the movement of oxygen vacancies in an oxide, under applied electrical field is an important ingredient.

In this poster we present a density functional theory study of oxygen vacancies in HfO₂ employing the electronic structure code juRS, a real-space finite-difference implementation of the projector augmented wave (PAW) method. First the optimized lattice parameters, band structures and band gaps are calculated for the three different crystalline phases of HfO₂ and compared with experimental results from literature. Then, the nature and stability of defects in different positions is studied in a monoclinic crystal supercell. Furthermore, we will present the energy barrier for defect migration on different paths using the nudged elastic band (NEB) method.

– Work is supported by SFB 917 (Nanoswitches).