Improved electronic structure and magnetic exchange interactions in transition metal oxides

Gopal, Priya; Gennaro, Riccardo De; Gusmão, Marta Silva dos Santos; Orabi, Rabih Al Rahal Al; Wang, Haihang; Curtarolo, Stefano; Fornari, Marco; Nardelli, Marco Buongiorno

doi:10.1088/1361-648x/aa8643

Cited by 36 publications

(30 citation statements)

References 74 publications

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“…Another notable fact is that U is applied to both metal and oxygen sites in oxides, where delocalized states should result in a very small U value from the above renormalization procedure. This method was originally tested on several benchmark materials (TiO 2 , MnO, NiO and wurtzite ZnO) and later on wide-gap semiconductors 47 and several other binary oxides 48 , showing improved agreement with more computationally-expensive beyond-DFT methods such as hybrid functionals and the GW approximation.…”

Section: Introductionmentioning

confidence: 99%

Improved description of perovskite oxide crystal structure and electronic properties using self-consistent Hubbard U corrections from ACBN0

May

Kolpak

2020

Phys. Rev. B

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The wide variety of complex physical behavior exhibited in transition metal oxides, particularly the perovskites ABO3, makes them a material family of interest in many research areas, but the drastically different electronic structures possible in these oxides raises challenges in describing them accurately within density functional theory (DFT) and related methods. Here we evaluate the ability of the ACBN0 "pseudo-hybrid" density functional, a recently developed first-principles approach to applying the Hubbard U correction, to describe the structural and electronic properties of the firstrow transition metal perovskites with (B = V − Ni). ACBN0 performs competitively with hybrid functional approaches such as the Heyd-Scuseria-Ernzerhof (HSE) functional even when they are optimized empirically, at a fraction of the computational cost. ACBN0 also describes both the structure and band gap of the oxides more accurately than a conventional Hubbard U correction performed by using U values taken from the literature. arXiv:1905.08328v1 [cond-mat.str-el]

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Section: Introductionmentioning

confidence: 99%

Improved description of perovskite oxide crystal structure and electronic properties using self-consistent Hubbard U corrections from ACBN0

May

Kolpak

2020

Phys. Rev. B

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“…In strongly correlated materials, one reason for the failure of DFT is the delocalization or self-interaction error [7,8], which can be partially fixed by adding a Hubbard U in the DFT+U approach [9]. This method recovers the insulating state in many materials that are incorrectly predicted to be metallic in DFT [9][10][11]. Moreover, DFT and DFT+U methods give quite accurate results for structural parameters in most materials [5,12].…”

Section: Introductionmentioning

confidence: 99%

“…Binary transition metal oxides (TMO) are among the most thoroughly studied strongly correlated materials [9-11, 13, 29-41], and thus are a natural starting point for generation of the training set. They include a number of wide-gap insulators predicted to be metallic in the con- ventional density functional formalism (DFT) [11,42]. Those that contain early and late transition metals are usually categorized as "Mott" and "charge-transfer" insulators in the "Zaanen-Sawatzky-Allen" scheme [43], and are insulating both above and below the Neel ordering temperature, with strongly localized 3d magnetic moments.…”

Section: Introductionmentioning

confidence: 99%

Systematic beyond-DFT study of binary transition metal oxides

et al. 2019

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Various methods going beyond density-functional theory (DFT), such as DFT+U, hybrid functionals, meta-GGAs, GW, and DFT-embedded dynamical mean field theory (eDMFT), have been developed to describe the electronic structure of correlated materials, but it is unclear how accurate these methods can be expected to be when applied to a given strongly correlated solid. It is thus of pressing interest to compare their accuracy as they apply to different categories of materials. Here, we introduce a novel paradigm in which a chosen set of beyond-DFT methods is systematically and uniformly tested on a chosen class of materials. For a first application, we choose the target materials to be the binary transition-metal oxides FeO, CoO, MnO, and NiO in their antiferromagnetic phase and present a head-to-head comparison of spectral properties as computed using the various methods. We also compare with available experimental angle-resolved photoemission spectroscopy (ARPES), inverse-photoemission spectroscopy, and with optical absorption. We find both B3LYP and eDMFT can reproduce the experiments quite well, with eDMFT doing best in particular when comparing with the ARPES data. arXiv:1907.10498v1 [cond-mat.str-el]

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“…Magnetic binary oxides with cubic rocksalt structure and the molecular formula MO, where M is a magnetic metal, like MnO, NiO, CoO, FeO, EuO, etc. form a group of insulating materials with antiferromagnetic alignment of atomic magnetic moments achieved by the superexchange interaction [1][2][3], except EuO, which is a ferromagnet [4]. These oxides are the best candidates for studying electronic behavior and exploring new phenomena that emerge in strongly-correlated electronic systems.…”

Section: Introductionmentioning

confidence: 99%

Pulsed Laser Deposition of Rocksalt Magnetic Binary Oxides

et al. 2019

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Magnetic binary oxides with the rocksalt structure constitute an important class of materials for potential applications as electronic or electrochemical devices. Moreover, they often become a theoretical playground, due to the simple electronic and crystal structures, in the quest for novel phenomena. For these possibilities to be realized, a necessary prerequisite would be to grow atomically ordered and controllably-strained binary oxides on proper substrates. Here we systematically explore the use of pulsed laser deposition technique (PLD) to grow three basic oxides that have rocksalt structure but different chemical stability in the ambient atmosphere: NiO (stable), MnO (metastable) and EuO (unstable). By tuning laser fluence FL, an epitaxial single-phase NiO thin-film growth can be achieved in a wide range of growth temperatures 10 ≤ TG ≤ 750 °C. At the lowest TG, the out-of-plane strain raises to 1.5%, which is five times higher than in NiO film grown at 750 °C. MnO thin films that had long-range order were successfully deposited on the MgO substrates after appropriate tuning of deposition parameters. The growth of MnO phase was strongly influenced by FL and the TG. EuO films with satisfactory quality were deposited by PLD after oxygen availability had been minimized. Synthesis of EuO thin films at rather low TG = 350 °C prevented thermally-driven lattice relaxation and allowed growth of strained films. Overall, PLD was a quick and reliable method to grow binary oxides with rocksalt structure in high quality that can satisfy requirements for applications and for basic research.Thin-film deposition is a technique that can be used to control strain in materials [22]. The Curie temperature TC of EuO thin film is strongly dependent on the strain and on film thickness tF [23]. Dislocations in NiO thin films locally change the magnetic ordering from antiferromagnetic to ferromagnetic [24]. Such 'ferromagnetic' dislocations originate from a local non-stoichiometry at in dislocation cores where Ni is deficient. A slight deviation from the stoichiometry also changes the conduction behavior in NiO thin films. Oxygendeficient EuO shows metallic behavior with a substantial increase of the TC to 120 K [25]. The deposition of high-quality magnetic binary oxides, and the ability to control the level of strain and density of defects in their structure, are challenging tasks in materials science and solid-state physics.Pulsed-laser deposition technique (PLD) has many advantages for growing thin films of high-quality oxides [26][27][28][29][30][31]. PLD can preserve the stoichiometry of the film composition,

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Improved electronic structure and magnetic exchange interactions in transition metal oxides

Cited by 36 publications

References 74 publications

Improved description of perovskite oxide crystal structure and electronic properties using self-consistent Hubbard U corrections from ACBN0

Improved description of perovskite oxide crystal structure and electronic properties using self-consistent Hubbard U corrections from ACBN0

Systematic beyond-DFT study of binary transition metal oxides

Pulsed Laser Deposition of Rocksalt Magnetic Binary Oxides

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