title: Evolutionary search for new high-k dielectric materials: methodology and applications to hafnia-based oxides.
abstract: High-k dielectric materials are important as gate oxides in microelectronics and as potential dielectrics for capacitors. In order to enable computational discovery of novel high-k dielectric materials, we propose a fitness model (energy storage density) that includes the dielectric constant, bandgap, and intrinsic breakdown field. This model, used as a fitness function in conjunction with first-principles calculations and the global optimization evolutionary algorithm USPEX, efficiently leads to practically important results. We found a number of high-fitness structures of SiO2 and HfO2, some of which correspond to known phases and some of which are new. The results allow us to propose characteristics (genes) common to high-fitness structures--these are the coordination polyhedra and their degree of distortion. Our variable-composition searches in the HfO2-SiO2 system uncovered several high-fitness states. This hybrid algorithm opens up a new avenue for discovering novel high-k dielectrics with both fixed and variable compositions, and will speed up the process of materials discovery.
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Qingfeng
authors: Q
authors: Zeng
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Artem R
authors: AR
authors: Oganov
authors: Department of Geosciences, Center for Materials by Design, and Institute for Advanced Computational Science, State University of New York, Stony Brook, NY 11794-2100, USA.
authors: Andriy O
authors: AO
authors: Lyakhov
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Congwei
authors: C
authors: Xie
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Xiaodong
authors: X
authors: Zhang
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Jin
authors: J
authors: Zhang
authors: Department of Geosciences, Center for Materials by Design, and Institute for Advanced Computational Science, State University of New York, Stony Brook, NY 11794-2100, USA.
authors: Qiang
authors: Q
authors: Zhu
authors: State Key Laboratory of Solidification Processing, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Bingqing
authors: B
authors: Wei
authors: Physics Department, New York City College of Technology, The City University of New York, Brooklyn, NY 11201, USA.
authors: Ilya
authors: I
authors: Grigorenko
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Litong
authors: L
authors: Zhang
authors: Science and Technology on Thermostructural Composite Materials Laboratory, and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
authors: Laifei
authors: L
authors: Cheng
keywords: computational materials discovery; dielectric materials; hafnia-based oxides