Coupled structural and magnetic antiphase domain walls on BaFe<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>2</mml:mn></mml:msub></mml:math>As<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>2</mml:mn></mml:msub></mml:math>

Li, Guorong; He, Xiaobo; Zhang, Jiandi; Jin, Rongying; Sefat, Athena S.; McGuire, Michael A.; Mandrus, David; Sales, B. C.; Plummer, E. W.

doi:10.1103/physrevb.86.060512

Cited by 14 publications

(21 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25 Antiphase DWs have been detected well below T N in BaFe 2 As 2 , and are likely to be mobile depending on the temperature. 26 Both types of DWs give rise to perturbations of the local hyperfine field and could be responsible for the slow dynamics we observe. 27 The DWs give rise to a low frequency tail in the spectra that is clearly evident in Fig.…”

Section: Resultsmentioning

confidence: 98%

Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2

Xiao

Dioguardi

et al. 2012

Phys. Rev. B

View full text Add to dashboard Cite

Resistivity, magnetization and microscopic 75 As nuclear magnetic resonance (NMR) measurements in the antiferromagnetically ordered state of the iron-based superconductor parent material CaFe2As2 exhibit anomalous features that are consistent with the collective freezing of domain walls. Below T * ≈ 10 K, the resistivity exhibits a peak and downturn, the bulk magnetization exhibits a sharp increase, and 75 As NMR measurements reveal the presence of slow fluctuations of the hyperfine field. These features in both the charge and spin response are strongly field dependent, are fully suppressed by H * ≈ 15 T, and suggest the presence of filamentary superconductivity nucleated at the antiphase domain walls in this material.

show abstract

Section: Resultsmentioning

confidence: 98%

Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2

Xiao

Dioguardi

et al. 2012

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…On the contrary, the STM/STS studies on the '122' family are still controversial although great efforts have been put in the studies [5][6][7][8][9][10][11][12] , with main debate focused on where and how the crystal cleaves. For example, within the BaFe 2 As 2 (Ba122) unit cell, the Fe-As layers have a mirror symmetry around the Ba layer as shown in Fig.…”

mentioning

confidence: 99%

Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe₂As₂Superconductors

Zou

et al. 2017

Nano Lett.

Self Cite

View full text Add to dashboard Cite

Combined scanning tunneling microscopy, spectroscopy and local barrier height (LBH) studies show that low-temperature-cleaved optimally-doped Ba(Fe 1-x Co x ) 2 As 2 crystals with x=0.06, with T c = 22 K, have complicated morphologies. Although the cleavage surface and hence the morphologies are variable, the superconducting gap maps show the same gap widths and nanometer size inhomogeneities irrelevant to the morphology. Based on the spectroscopy and LBH maps, the bright patches and dark stripes in the morphologies are identified as Ba and As dominated surface terminations, respectively. Magnetic impurities, possibly due to cobalt or Fe atoms, are believed to create local in-gap state and in addition suppress the superconducting coherence peaks. This study will clarify the confusion on the cleavage surface terminations of the Fe-based superconductors, and its relation with the electronic structures.One major difference between the iron-based superconductors (FeSC) and conventional superconductors is the necessary involvement of magnetic elements. For a long time magnetic elements had been thought to suppress the superconductivity because of the competitive nature of superconductivity and magnetism, but with the cuprates and now FeSC, there are two cases of high-temperature superconductivity that apparently are magnetic in origin [1][2][3][4] .FeSC share a common Fe 2 X 2 layer structure where X is a pnictogen (P, As) or a chalcogen (S, Se, Te). With the incorporation of intercalation layers between the Fe 2 X 2 layers, FeSC are classified into five families: '11', '111', '122', '1111' and complex structure materials 3-4 . To understand the causes of this superconductivity, the relationship between the global properties and local behavior must be understood. These local signatures include chemical defects, electronic variations, dopant distributions, and strain. The '11' and '111' families have been studied extensively using scanning tunneling microscopy and spectroscopy (STM/STS) and the results are clear due to the cleanness of the cleavage as there is unique and symmetric cleavage plane, 1 and a non-polar surface with minimal surface effect [5][6] . On the contrary, the STM/STS studies on the '122' family are still controversial although great efforts have been put in the studies [5][6][7][8][9][10][11][12] , with main debate focused on where and how the crystal cleaves. For example, within the BaFe 2 As 2 (Ba122) unit cell, the Fe-As layers have a mirror symmetry around the Ba layer as shown in Fig. 1 (a). As FeAs layer is a highly polar plane, the physical cleavage through this plane might force Ba ions to be divided to both sides of the cleavage surface to alleviate the polar nature, associated with surface reconstructing. As a result, rich morphologies or "terminations" exist on the Ba122 cleavage surface. Some groups report that the crystal cleaves at Ba plane with ½ monolayer of Ba atoms to achieve the charge neutral surface 7-10 , while others suggest As atoms terminate the surface by breaking the we...

show abstract

“…Mazin and Johannes (19) describe a model with dynamic twin and antiphase spin domain walls that seems to explain many experimental observations, including the temperature separation of the structural and magnetic transitions. Our recent scanning tunneling microscopy (STM) measurements show that the surface can stabilize these dynamic fluctuations at a structural antiphase boundary (20).Cleaving a single crystal to create a surface breaks the translational symmetry and thus, disturbs the delicate balance between structure and magnetism, which may result in completely new emergent behavior. A hypothetical surface phase diagram for the Co doped Ba122 system, based on the electron energy…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Anomalous surface lattice dynamics in the low-temperature phase of Ba(Fe _{1−
x} Co _x ) ₂ As ₂

Teng

Chen

Xiong

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

In complex materials, how correlation between charge, spin, and lattice affects the emergent phenomena remains unclear. The newly discovered iron-based high-temperature superconductors and related compounds present to the community a prototype family of materials, where interplay between charge, spin, and lattice degrees of freedom can be explored. With the occurrence of structural, magnetic, and superconducting transitions in the bulk of these materials, creating a surface will change the delicate balance between these phases, resulting in new behavior. A surface lattice dynamics study on (001) Ba(Fe 1−x Co x ) 2 As 2 , through electron energy loss spectroscopy measurements, reveals unusual temperature dependence of both the phonon frequency and line width in the low-temperature orthorhombic phase. The rate of change of phonon frequency with temperature is gigantic, two orders of magnitude larger than in the bulk. This behavior cannot be explained using conventional models of anharmonicity or electron-phonon coupling; instead, it requires that a large surface-spin-charge-lattice coupling be included. Furthermore, the higher surface-phase-transition temperature driven by surface stabilization of the low-temperature orthorhombic phase seems to turn the first-order transition (bulk) into the second-order type, equivalent to what is observed in the bulk by applying a uniaxial pressure. Such equivalence indicates that the surface mirrors the bulk under extreme conditions. spin-lattice coupling | structure transition | magnetic ordering | surface versus bulk T he recent discovery of high-temperature superconductivity in layered iron-based compounds (1) has created enormous activity in the scientific community. One of the most intriguing aspects of these new compounds is the intimate coupling between spin and lattice, offering a wonderful platform to study and manipulate their relationship. The parent compounds (no disorder induced by doping) of the 122 family [Alkaline earth (A) Fe 2 As 2 ] exhibit a coupled magnetic and structural transition from the lowtemperature (LT) antiferromagnetic orthorhombic phase to a high-temperature (HT) paramagnetic tetragonal phase (2-4), which has the signature of being first order in the bulk. Fig. 1A shows the phase diagram for the compound of interest in this paper, Ba(Fe 1−x Co x ) 2 As 2 (3), where doping the parent compound (Co for Fe) lowers the transition temperatures and at x ∼ 2.2%, there seems to be a tricritical point beyond which the magnetic transition becomes second order (2, 4). The strong spin-lattice coupling in these systems (4-7), along with the presence of a tricritical point, creates an environment where either strongly firstorder or nearly second-order phase transitions may be observed. Creating a surface by cleaving these layered materials is a controlled way to tip the balance between competing phases, thus providing a unique opportunity to study the subtle aspects of the interactions between lattice and spin through charge. Important for this study is the fac...

show abstract

Coupled structural and magnetic antiphase domain walls on BaFe2As2

Cited by 14 publications

References 24 publications

Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2

Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2

Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe₂As₂Superconductors

Anomalous surface lattice dynamics in the low-temperature phase of Ba(Fe _{1−
x} Co _x ) ₂ As ₂

Contact Info

Product

Resources

About

Coupled structural and magnetic antiphase domain walls on BaFe2As2

Cited by 14 publications

References 24 publications

Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2

Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2As2

Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe2As2Superconductors

Anomalous surface lattice dynamics in the low-temperature phase of Ba(Fe 1− x Co x ) 2 As 2

Contact Info

Product

Resources

About

Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe₂As₂Superconductors

Anomalous surface lattice dynamics in the low-temperature phase of Ba(Fe _{1−
x} Co _x ) ₂ As ₂