Chemical stability and defect formation in CaHfO
                    <sub>3</sub>

Alay-e-Abbas, Syed Muhammad; Nazir, S.; Wong, Kin Mun; Shaukat, A.; Schwingenschlögl, Udo

doi:10.1209/0295-5075/106/27003

Cited by 18 publications

(3 citation statements)

References 37 publications

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“…Candidates include SrZrO 3 , CaZrO 3 or CaHfO 3 . DFT simulations predict that this latter compound, that includes the 5d element Hf, can be made metallic through doping with oxygen vacancies 30 , similar to STO and KTO, which suggests that it may host a 2DEG when interfaced with another oxide.…”

Section: Discussionmentioning

confidence: 98%

Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO3 interfaces

et al. 2022

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Rashba interfaces have emerged as promising platforms for spin-charge interconversion through the direct and inverse Edelstein effects. Notably, oxide-based two-dimensional electron gases display a large and gate-tunable conversion efficiency, as determined by transport measurements. However, a direct visualization of the Rashba-split bands in oxide two-dimensional electron gases is lacking, which hampers an advanced understanding of their rich spin-orbit physics. Here, we investigate KTaO3 two-dimensional electron gases and evidence their Rashba-split bands using angle resolved photoemission spectroscopy. Fitting the bands with a tight-binding Hamiltonian, we extract the effective Rashba coefficient and bring insight into the complex multiorbital nature of the band structure. Our calculations reveal unconventional spin and orbital textures, showing compensation effects from quasi-degenerate band pairs which strongly depend on in-plane anisotropy. We compute the band-resolved spin and orbital Edelstein effects, and predict interconversion efficiencies exceeding those of other oxide two-dimensional electron gases. Finally, we suggest design rules for Rashba systems to optimize spin-charge interconversion performance.

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Section: Discussionmentioning

confidence: 98%

Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO3 interfaces

et al. 2022

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“…This atomic chemical potential depends on specific equilibrium growth conditions.

E_{F}

is the Fermi level referenced to the valence band maximum (VBM)

E_{VBM}

of the perfect system, which can be expressed as the total energy difference of bulk system between 0 and

+ 1

charged states .

△ E_{F}

can range from the VBM (0) to conduction band minimum (CBM, the bandgap

E_{g}

) for non‐degenerate system.…”

Section: Calculation Proceduresmentioning

confidence: 99%

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

Dai

Wang

et al. 2016

Physica Status Solidi (b)

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Using hybrid density functional calculations, this paper systematically investigated the common defects in m‐HfO2 and β‐Si3N4 trapping layer, respectively, on the performance of charge trapping memory (CTM) devices. Defects may act as charge traps or fixed charges, however, only traps can be used to store charges. Thus, firstly, the paper distinguished traps or fixed charges of defects in trapping layer through the band alignment method. Then we can restrain the formation of defects that act as fixed charges in manufacturing CTM devices, which is very meaningful in improving the performance of CTM. Secondly, it studied the storage performance of traps in m‐HfO2 and β‐Si3N4 by analyzing the formation energy, the atomistic structural change during program/erase (P/E) cycles, and localization energy. The simulation results found that only some defects can be charge traps in m‐HfO2 and β‐Si3N4, and the charge transition of these traps only appeared between certain charged states. In addition, these traps show reversible structural change during P/E cycles and different localizing abilities for holes and electrons. Therefore, this study would provide some theoretical guidance for improving the performance of CTM.

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“…This compound has a wide bandgap of 6.4 eV and a high dielectric constant. Insulating to half metallic transition has been theoretically predicted in this compound due to the presence of higher concentration of O-defects [25]. Furthermore, it is optically transparent in the range of visible to deep ultraviolet light, making it a suitable candidate for optoelectronic devices [26][27][28].…”

Section: Introductionmentioning

confidence: 97%

Emergence of low-temperature glassy dynamics in Ru substituted non-magnetic insulator CaHfO₃

Kaur¹,

Mukherjee²

2022

J. Phys.: Condens. Matter

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Non–magnetic insulators/semiconductors with induced magnetism introduced via transition metal substitution are one of the promising materials in the field of spintronic, magnetoelectronics and magneto–optical devices. In this context, here, we focus on magnetism induced in a non–magnetic insulator CaHfO3, by the substitution of 4d element Ru, at Hf–site. Structural investigations indicate that substitution of Ru4+ (up to 50%) does not affect the original crystal structure of the parent compound. Magnetic studies divulge a crossover from a diamagnetic to paramagnetic state with 20% Ru substitution. Further replacement of Hf results in a glassy magnetic state in CaHf1-xRuxO3 (0.3 ≤ x ≤ 0.5). The nature of the low temperature glassiness (below 20 K) in these compositions is confirmed through Vogel–Fulcher and Power law, along with, magnetic memory effect and relaxation dynamics. The observed glassiness is explained through the phenomenological “hierarchical model”. Our studies indicate that the presence of competing short range interactions among randomly arranged Ru cations in non–magnetic insulator CaHfO3 are responsible for the observed low temperature magnetic state in this series with compositions > 0.25.

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Chemical stability and defect formation in CaHfO ₃

Cited by 18 publications

References 37 publications

Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO3 interfaces

Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO3 interfaces

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

Emergence of low-temperature glassy dynamics in Ru substituted non-magnetic insulator CaHfO₃

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Chemical stability and defect formation in CaHfO 3

Cited by 18 publications

References 37 publications

Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO3 interfaces

Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO3 interfaces

Impact of native defects and impurities in m−HfO2 and β−Si3N4 on charge trapping memory devices: A first principle hybrid functional study

Emergence of low-temperature glassy dynamics in Ru substituted non-magnetic insulator CaHfO3

Contact Info

Product

Resources

About

Chemical stability and defect formation in CaHfO ₃

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

Emergence of low-temperature glassy dynamics in Ru substituted non-magnetic insulator CaHfO₃