First‐Principles Calculations of the Structure Stability and Mechanical Properties of LiFeAs and NaFeAs under Pressure

Hu, Zhengquan; Xu, Weiwei; Liu, Huan

doi:10.1155/2018/3219685

Cited by 8 publications

(2 citation statements)

References 41 publications

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“…Ultrasoft pseudopotential is assigned, and density mixing is chosen to be the electronic minimizer [ 31 , 32 , 33 , 34 , 35 ]. The experimental lattice parameters are used [ 36 , 37 ]. In this article, only Fe and As atoms are imported for the 111-type compounds.…”

Section: Methodsmentioning

confidence: 99%

Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO3 Superconductors

Wong

Lortz

2023

Materials

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Many theoretical models of iron-based superconductors (IBSC) have been proposed, but the superconducting transition temperature (Tc) calculations based on these models are usually missing. We have chosen two models of iron-based superconductors from the literature and computed the Tc values accordingly; recently two models have been announced which suggest that the superconducting electron concentration involved in the pairing mechanism of iron-based superconductors may have been underestimated and that the antiferromagnetism and the induced xy potential may even have a dramatic amplification effect on electron–phonon coupling. We use bulk FeSe, LiFeAs and NaFeAs data to calculate the Tc based on these models and test if the combined model can predict the superconducting transition temperature (Tc) of the nanostructured FeSe monolayer well. To substantiate the recently announced xy potential in the literature, we create a two-channel model to separately superimpose the dynamics of the electron in the upper and lower tetrahedral plane. The results of our two-channel model support the literature data. While scientists are still searching for a universal DFT functional that can describe the pairing mechanism of all iron-based superconductors, we base our model on the ARPES data to propose an empirical combination of a DFT functional for revising the electron–phonon scattering matrix in the superconducting state, which ensures that all electrons involved in iron-based superconductivity are included in the computation. Our computational model takes into account this amplifying effect of antiferromagnetism and the correction of the electron–phonon scattering matrix, together with the abnormal soft out-of-plane lattice vibration of the layered structure. This allows us to calculate theoretical Tc values of LiFeAs, NaFeAs and FeSe as a function of pressure that correspond reasonably well to the experimental values. More importantly, by taking into account the interfacial effect between an FeSe monolayer and its SrTiO3 substrate as an additional gain factor, our calculated Tc value is up to 91 K and provides evidence that the strong Tc enhancement recently observed in such monolayers with Tc reaching 100 K may be contributed from the electrons within the ARPES range.

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Section: Methodsmentioning

confidence: 99%

Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO3 Superconductors

Wong

Lortz

2023

Materials

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show abstract

“…The phonon data are calculated in finite displacement mode where the supercell defined by cutoff radius is 5Å and the interval of the dispersion is 0.04(1/Å). The experimental lattice parameters are used [37,38]. In this article, only Fe and As atoms are imported for the 111-type compounds.…”

Section: Methodsmentioning

confidence: 99%

Preliminary TC Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO<sub>3</sub> Superconductors

Wong¹,

Lortz²

2023

Preprint

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Many theoretical models of iron-based superconductors have been proposed but Tc calculations based on the models are usually missing. We have chosen two models of iron-based superconductors in the literature and then compute the Tc values accordingly: Recently two models have been announced which suggest that superconducting electron concentration involved in the pairing mechanism of iron-based superconductors may have been underestimated, and that the antiferromagnetism and the induced xy potential may even have a dramatic amplification effect on electron-phonon coupling. We use bulk FeSe, LiFeAs and NaFeAs data to calculate the Tc based on these models and test if the combined model can predict the superconducting transition temperature (Tc) of the nanostructured FeSe monolayer well. To substantiate the recently announced xy potential in the literature, we create a two-channel model to separately superimpose the dynamics of the electron in the upper and lower tetrahedral plane. The results of our two-channel model support the literature data. While scientists are still searching for a universal DFT functional that can describe the pairing mechanism of all iron-based superconductors, we base on the ARPES data to propose an empirical combination of DFT functional for revising the electron-phonon scattering matrix in the superconducting state, which ensures that all electrons involved in iron-based superconductivity are included in the computation. Our computational model takes into account this amplifying effect of antiferromagnetism and the correction of the electron-phonon scattering matrix together with the abnormal soft out-of-plane lattice vibration of the layered structure, which allows us to calculate theoretical Tc values of LiFeAs, NaFeAs and FeSe as a function of pressure that correspond reasonably well to the experimental values. More importantly, by taking into account the interfacial effect between an FeSe monolayer and its SrTiO3 substrate as an additional gain factor, our calculated Tc value is up to 91 K high, and provides evidence that the strong Tc enhancement recently observed in such monolayers with Tc reaching 100 K may be contributed from the electrons within the ARPES range.

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Investigation of pressure impact on physical characteristics of FeSe chalcogenide superconductor: Insights from first principles calculation

Hota,

Mohanta

2024

Computational Materials Science

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First‐Principles Calculations of the Structure Stability and Mechanical Properties of LiFeAs and NaFeAs under Pressure

Cited by 8 publications

References 41 publications

Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO3 Superconductors

Preliminary Tc Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO3 Superconductors

Preliminary TC Calculations for Iron-Based Superconductivity in NaFeAs, LiFeAs, FeSe and Nanostructured FeSe/SrTiO<sub>3</sub> Superconductors

Investigation of pressure impact on physical characteristics of FeSe chalcogenide superconductor: Insights from first principles calculation

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