Impact of polytypism on the ground state properties of zinc oxide: A first-principles study

Menad, A.; Benmalti, M.E.; Zaoui, A.; Ferhat, M.

doi:10.1016/j.rinp.2020.103316

Cited by 11 publications

(4 citation statements)

References 57 publications

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“…The trigonal symmetry of the HfC_polytype remains high and can easily be transformed into a hexagonal setting (shown in Table 2 and Figure 2d). The polytypic behavior has previously been experimentally observed in various chemical systems [73][74][75] and theoretically computed [76,77] in various chemical systems; in the HfC compound, it appears in high-temperature conditions as a metastable phase (Figure 1).…”

Section: Crystal Structure Prediction and Polymorphs Of Hfcsupporting

confidence: 54%

Hafnium Carbide: Prediction of Crystalline Structures and Investigation of Mechanical Properties

Zagorac,

Schön,

Matović

et al. 2024

Crystals

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Hafnium carbide (HfC) is a refractory compound known for its exceptional mechanical, thermal, and electrical properties. This compound has gained significant attention in materials science and engineering due to its high melting point, extreme hardness, and excellent thermal stability. This study presents crystal structure prediction via energy landscape explorations of pristine hafnium carbide supplemented by data mining. Apart from the well-known equilibrium rock salt phase, we predict eight new polymorphs of HfC. The predicted HfC phases appear in the energy landscape with known structure types such as the WC type, NiAs type, 5-5 type, sphalerite (ZnS) type, TlI type, and CsCl type; in addition, we predict two new structure types denoted as ortho_HfC and HfC_polytype, respectively. Moreover, we have investigated the structural characteristics and mechanical properties of hafnium carbide at the DFT level of computation, which opens diverse applications in various technological domains.

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Section: Crystal Structure Prediction and Polymorphs Of Hfcsupporting

confidence: 54%

Hafnium Carbide: Prediction of Crystalline Structures and Investigation of Mechanical Properties

Zagorac,

Schön,

Matović

et al. 2024

Crystals

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“…DFT-1/2 has also been applied to diamond [179], Gecontaining semiconductors [180,181], SiC [182,183], III-V semiconductors , spinel nitrides [217], EuS [218], MgTe [219], doped K 0.5 Na 0.5 NbO 3 [220,221], halide perovskites [222][223][224][225][226][227][228][229][230][231][232][233][234][235], II-VI semiconductors [236][237][238][239][240][241][242][243][244], WO 3 [245], LiGa 5 O 8 [246], silicon surfaces [247][248][249][250][251][252][253][254][255], alkaline earth fluorides [147], Ca oxides [256], SnO 2 [257], Be-VI polymorphs…”

Section: Bulk Electronic Band Structure Calculationmentioning

confidence: 99%

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

Mao

Yan

Xue

et al. 2022

J. Phys.: Condens. Matter

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It is known that the Kohn-Sham eigenvalues do not characterize experimental excitation energies directly, and the band gap of a semiconductor is typically underestimated by local density approximation (LDA) of density functional theory (DFT). An embarrassing situation is that one usually uses LDA+U for strongly correlated materials with rectified band gaps, but for non-strongly-correlated semiconductors one has to resort to expensive methods like hybrid functionals or GW. In spite of the state-of-the-art meta-GGA functionals like TB09 and SCAN, methods with LDA-level complexity to rectify the semiconductor band gaps are in high demand. DFT-1/2 stands as a feasible approach and has been more widely used in recent years. In this work we give a detailed derivation of the Slater half occupation technique, and review the assumptions made by DFT-1/2 in semiconductor band structure calculations. In particular, the self-energy potential approach is verified through mathematical derivations. The aims, features and principles of shell DFT-1/2 for covalent semiconductors are also accounted for in great detail. Other developments of DFT-1/2 including conduction band correction, DFT+A-1/2, empirical formula for the self-energy potential cutoff radius, etc., are further reviewed. The relations of DFT-1/2 to hybrid functional, sX-LDA, GW, self-interaction correction, scissor’s operator as well as DFT+U are explained. Applications, issues and limitations of DFT-1/2 are comprehensively included in this review.

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“…2b and 2c). They were recently reported as theoretical stable structures of ZnO that may allow a fine-tune of electronic properties [21,22,46]. The three structures were fully optimized at DFT and DFT+U levels.…”

Section: Ab Initio Calculationsmentioning

confidence: 99%

Experimental and ab initio study of the structural and optical properties of ZnO coatings: Performance of the DFT+U approach

Apaolaza

Richard

Tejerina

2020

PAC

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In this work, ZnO coatings were produced by the spray-pyrolysis technique and characterized by scanning electron microscopy, X-ray diffraction and optical transmittance spectroscopy. The experimental results were compared to predictions obtained from electronic-structure calculations based on the Density Functional Theory plus U (DFT+U) approach. To this purpose, the 2H, 4H and 6H polytypes of ZnO were theoretically analysed, and DFT+U was assessed for the calculation of structural, electronic and optical properties of the hexagonal ZnO structures. We found that DFT+U is an effective and accurate method that combined with experimental measurements, allows a deeper insight about the coatings of the wurtzite (2H) phase synthesized in the laboratory. This comprehensive study of the pure ZnO is the first step towards the study of more complex ZnO-based coatings.

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Impact of polytypism on the ground state properties of zinc oxide: A first-principles study

Cited by 11 publications

References 57 publications

Hafnium Carbide: Prediction of Crystalline Structures and Investigation of Mechanical Properties

Hafnium Carbide: Prediction of Crystalline Structures and Investigation of Mechanical Properties

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

Experimental and ab initio study of the structural and optical properties of ZnO coatings: Performance of the DFT+U approach

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