Extensive hydrogen incorporation is not necessary for superconductivity in topotactically reduced nickelates

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 27, 2024

Abstract A key open question in the study of layered superconducting nickelate films is role that hydrogen incorporation into lattice plays appearance state. Due to challenges stabilizing highly crystalline square planar films, are prepared by deposition a more stable parent compound which then transformed target phase via topotactic reaction with strongly reducing agent such as CaH 2 . Recent studies, both experimental and theoretical, have introduced possibility from may be critical for superconductivity. In this work, we use secondary ion mass spectrometry examine La 1− x X NiO / SrTiO 3 ( = Ca Sr) Nd 6 Ni 5 O 12 NdGaO along non-superconducting NdNiO (Nd,Sr)NiO We find no evidence extensive across broad range samples, including films. Theoretical calculations indicate broadly energetically unfavorable these systems, supporting our conclusion not generally required achieve state square-planar nickelates.

Language: Английский

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Hardening of Ni-O bond-stretching phonons in LaNiO2

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(8)

Published: Feb. 6, 2025

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My life in science: Lessons for yours?

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(1)

Published: Jan. 5, 2024

Because of an acquired obsession to understand as much possible in a limited but important area science and because optimism, luck, help from others, my life turned out be better than I or others could have expected planned. This is the story how that happened, also groundstate density functional theory electronic structure, told personal perspective.

Language: Английский

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Charge ordering as the driving mechanism for superconductivity in rare-earth nickel oxides

Physical Review Materials, Journal Year: 2024, Volume and Issue: 8(6)

Published: June 4, 2024

Superconductivity is one of the most intriguing properties matter, described by an attractive interaction that binds electrons into Cooper pairs. To date, highest critical temperature at ambient conditions achieved in copper oxides. While layered nickel oxides were long proposed to be analogous cuprates, superconductivity was only demonstrated 2019 albeit without clarifying pairing mechanism. Here we use density functional theory show nickelates driven electron-phonon coupling originating from a charge ordering. Due intrinsic electronic instability half-doped compounds, $\mathrm{N}{\mathrm{i}}^{1.5+}$ cations dismutate more stable $\mathrm{N}{\mathrm{i}}^{+}$ and $\mathrm{N}{\mathrm{i}}^{2+}$ cations, which accompanied bond disproportionation $\mathrm{Ni}{\mathrm{O}}_{4}$ complexes producing insulating charge-ordered state. Once doping suppresses instability, vibration sufficient reproduce key characteristic observed experimentally, notably dome ${T}_{c}$ as function content. These phenomena are identified if relevant degrees freedom well exchange-correlation sufficiently amends self-interaction errors involved simulations. Finally, despite presence correlation effects inherent $3d$ elements favor formation local Ni spins, mechanism behind pairs nickelate superconductors appears similar nonmagnetic bismuth oxide superconductors.

Language: Английский

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DFT+DMFT study of the magnetic susceptibility and the correlated electronic structure in transition-metal intercalated NbS2

Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 109(8)

Published: Feb. 7, 2024

The Co-intercalated ${\mathrm{NbS}}_{2}$ (${\mathrm{Co}}_{1/3}{\mathrm{NbS}}_{2}$) compound exhibits large anomalous Hall conductance, likely due to the noncoplanar magnetic ordering of Co spins. In this work, we study relation between novel magnetism and correlated electronic structure ${\mathrm{Co}}_{1/3}{\mathrm{NbS}}_{2}$ by adopting dynamical mean-field theory (DMFT) treat correlation effect $d$ orbitals. We find that hole doping can tune size Nb pocket at DMFT Fermi surface, producing features consistent with those observed in angle-resolved photoemission spectra [H. Tanaka et al., Phys. Rev. B 105, L121102 (2022)]. also compute momentum-resolved spin susceptibility correlate it surface shape. wave vector obtained from peak agrees one experimentally neutron scattering; is compatible a commensurate $3q$ structure. discuss how results change if other than transition-metal intercalations are used.

Language: Английский

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Microscopic Magnetism of Nickel-Based Infinite-Layer Superconducting Parent Compounds RNiO₂ (R = La, Nd): A μSR Study

Chinese Physics Letters, Journal Year: 2024, Volume and Issue: 41(9), P. 097502 - 097502

Published: Aug. 8, 2024

Abstract By using muon spin relaxation (μSR) measurements, we perform a comparative study of the microscopic magnetism in parent compounds infinite-layer nickelate superconductors R NiO 2 ( = La, Nd). In either compound, zero-field μSR spectra down to lowest measured temperature reveal no long-range magnetic order. LaNiO , short-range correlations appear below T 150 K, and spins fully freeze ∼ 10 K. NdNiO exhibits more complex dynamics driven by Nd 4 f Ni 3 d electron fluctuations. Further, it shows features suggesting proximity spin-glass state occurring 5 both compounds, behavior with is further confirmed longitudinal-field measurements. These results provide new insight into superconducting nickelates, crucial understanding origin their superconductivity.

Language: Английский

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