Pressure-induced transition to the collapsed tetragonal phase in 
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Naumov, Pavel G.; Filsinger, Kai Alexander; Barkalov, O. I.; Fecher, Gerhard H.; Medvediev, Sergiy; Felser, Claudia

doi:10.1103/physrevb.95.144106

Cited by 16 publications

(11 citation statements)

References 27 publications

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“…ARPES measurements indicate reduction in electron correlation effects involving the nominally 3d 4 Cr +2 cations where the band renormalization is smaller than in BaFe 2 As 2 [23,24]. Additionally, recent electrical resistivity and x-ray diffraction measurements on single and polycrystals of BaCr 2 As 2 under high pressure revealed a tetragonal to collapsed tetragonal (cT) transition at ∼ 18.5 GPa [25]. The cT phase has also been manifested in CaCo 1.86 As 2 at ambient pressure [26] and in CaFe 2 As 2 and SrCo 2 As 2 under high pressures [27,28].…”

Section: Introductionmentioning

confidence: 97%

Itinerant G-type antiferromagnetic order inSrCr2As2

et al. 2017

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Neutron diffraction and magnetic susceptibility studies of a polycrystalline SrCr2As2 sample reveal that this compound is an itinerant G-type antiferromagnet below the Néel temperature TN = 590(5) K with the Cr magnetic moments aligned along the tetragonal c axis. The system remains tetragonal to the lowest measured temperature (∼12 K). The lattice parameter ratio c/a and the magnetic moment saturate at about the same temperature below ∼ 200 K, indicating a possible magnetoelastic coupling. The ordered moment, µ = 1.9(1) µB/Cr, measured at T = 12 K, is significantly reduced compared to its localized value (4 µB/Cr) due to the itinerant character brought about by the hybridization between the Cr 3d and As 4p orbitals.

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Section: Introductionmentioning

confidence: 97%

Itinerant G-type antiferromagnetic order inSrCr2As2

et al. 2017

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“…In addition to the previously mentioned electronic and structural phase transitions, another structural instability is well known for those systems crystallizing in the ThCr 2 Si 2 structure, [ 63–68 ] such as the A Fe 2 As 2 and

A e

Fe 2 As 2 (

A =

alkali and

A e =

alkaline‐earth metal) systems. [ 17,69,70 ] The formation of

p_{z}

bonds in case of a sufficiently short As interlayer distance [ 63 ] (see Figure 1e for the non‐polarized electron density across the collapsed Ca layer in CaKFe 4 As 4 ) results in a structural phase transition from the regular, uncollapsed tetragonal structure (tet or ucT) to the so‐called collapsed tetragonal (cT) structure.…”

Section: Introductionmentioning

confidence: 99%

Hydrostatic and Uniaxial Pressure Tuning of Iron‐Based Superconductors: Insights into Superconductivity, Magnetism, Nematicity, and Collapsed Tetragonal Transitions

Gati

Bud’ko

et al. 2020

Annalen der Physik

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Iron-based superconductors are well-known for their intriguing phase diagrams, which manifest a complex interplay of electronic, magnetic, and structural degrees of freedom. Among the phase transitions observed are superconducting, magnetic, and several types of structural transitions, including a tetragonal-to-orthorhombic and a collapsed-tetragonal transition. In particular, the widely observed tetragonal-to-orthorhombic transition is believed to be a result of an electronic order that is coupled to the crystalline lattice and is, thus, referred to as nematic transition. Nematicity is therefore a prominent feature of these materials, which signals the importance of the coupling of electronic and lattice properties. Correspondingly, these systems are particularly susceptible to tuning via pressure (hydrostatic, uniaxial, or some combination). Efforts to probe the phase diagrams of pressure-tuned iron-based superconductors are reviewed with a strong focus on recent insights into the phase diagrams of several members of this material class under hydrostatic pressure. These studies on FeSe, Ba(Fe 1−x Co x) 2 As 2 , Ca(Fe 1−x Co x) 2 As 2 , and CaK(Fe 1−x Ni x) 4 As 4 are, to a significant extent, made possible by advances of what measurements can be adapted to their use under differing pressure environments. The potential impact of these tools for the study of the wider class of strongly correlated electron systems is pointed out.

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“…K122 [11,12], Ca122 [13], Ba122 [14,15] and Eu122 [16]), but also for other compounds with the ThCr 2 Si 2 -type structure (e.g. SrRh 2 P 2 [17], CaFe 2 P 2 [18], EuFe 2 P 2 [19], SrCo 2 As 2 [20] or BaCr 2 As 2 [21]).…”

Section: Introductionmentioning

confidence: 99%

Structural, electronic, and dynamical properties of the tetragonal and collapsed tetragonal phases of KFe2As2

et al. 2019

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Compounds with a tetragonal ThCr2Si2-type structure are characterized by the possibility of the isostructural phase transition from the tetragonal phase to the collapsed tetragonal phase induced by the external pressure. An example of a compound with such a phase transition is KFe2As2, which belongs to the family of the iron-based superconductors. In this paper, we investigate the effects of the phase transition on the structural, electronic, and dynamical properties of this compound. Performing the ab initio calculations, we reproduce the dependence of the lattice constants on pressure and analyze the changes of the inter-atomic distances in the tetragonal and collapsed tetragonal phases. Using the tight binding model with maximally localized Wannier orbitals, we calculate and discuss the influence of pressure on the electronic band structure as well as on the shape of the Fermi surface. We found a precursor of the phase transition in the form of enhancement of overlapping between two Wannier orbitals of As atoms. In order to better understand the superconducting properties of KFe2As2, we study the orbital-projected Cooper pairs susceptibility as a function of pressure. We found a decrease of susceptibility with the increasing pressure in a good qualitative agreement with experimental observation. The structural transition also influences the phonon spectrum of KFe2As2, which exhibits pronounced changes induced by pressure. Some phonon modes related with the vibrations of Fe and As atoms show an anomalous, nonmonotonic dependence on pressure close to the phase transition. *

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Pressure-induced transition to the collapsed tetragonal phase in BaCr2As2

Cited by 16 publications

References 27 publications

Itinerant G-type antiferromagnetic order inSrCr2As2

Itinerant G-type antiferromagnetic order inSrCr2As2

Hydrostatic and Uniaxial Pressure Tuning of Iron‐Based Superconductors: Insights into Superconductivity, Magnetism, Nematicity, and Collapsed Tetragonal Transitions

Structural, electronic, and dynamical properties of the tetragonal and collapsed tetragonal phases of KFe2As2

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