Tetragonal-to-Orthorhombic Structural Phase Transition at 90 K in the Superconductor<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>Fe</mml:mi><mml:mn>1.01</mml:mn></mml:msub><mml:mi>Se</mml:mi></mml:math>

McQueen, Tyrel M.; Williams, A. J.; Stephens, Peter W.; Tao, Jing; Zhu, Yimei; Ksenofontov, Vadim; Casper, F.; Felser, Claudia; Cava, R. J.

doi:10.1103/physrevlett.103.057002

Cited by 492 publications

(513 citation statements)

References 21 publications

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“…al. reported that superconducting FeSe undergoes a structural transition from tetragonal to orthorhombic at 90 K but that non-superconducting FeSe does not undergo this transition [23]. With pressure, the T c of FeSe increased to 34 K [24,25].…”

Section: Resultsmentioning

confidence: 96%

Pulsed laser deposition conditions and superconductivity of FeSe thin films

et al. 2011

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We report the effects of growth conditions on the superconducting properties of FeSe films epitaxially grown on LaAlO 3 substrates by pulsed laser deposition (PLD). Customary materials characterization techniques [X-ray diffraction (XRD), in-situ X-ray photoelectron spectroscopy (XPS), in-situ ultra-violet photoelectron spectroscopy (UPS), and scanning electron microscopy (SEM)] revealed the films had a c-axis oriented tetragonal structure with lattice constants dependent on the growth temperature (varied from 100 to 600°C). The standard four-point probe method was used to measure the resistivity and superconducting transitions. Films grown at 400-550°C showed a clear superconducting onset but no zero resistance down to

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Section: Resultsmentioning

confidence: 96%

Pulsed laser deposition conditions and superconductivity of FeSe thin films

et al. 2011

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“…3 Additionally, Fe 1.01 Se undergoes a structural transition from tetragonal to orthorhombic at 90 K whereas the same transition in Fe 1.03 Se is not observed. 8 These results show the strong dependence between the properties of these materials and their composition.…”

Section: Introductionmentioning

confidence: 81%

“…43 Experimentally, low temperature electron diffraction measurements on FeSe show changes in symmetry that result in the presence of the "striping" pattern; however, an effective magnetic moment was not determined in this case. 8 The local moments residing on the Fe net atoms in the striped "FeS" model are ±1.51 μ B /Fe for Berner's structure and ±1.21 Although the values of these calculated moments may be imprecise because they are determined using LSDA, trends can still be inferred about the relative magnitudes and signs of moments on inequivalent magnetically active sites. Table 2).…”

Section: Magnetic Orderingmentioning

confidence: 96%

Validation of Interstitial Iron and Consequences of Nonstoichiometry in Mackinawite (Fe_1+xS)

Brgoch

Miller

2012

J. Phys. Chem. A

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A theoretical investigation of the relationship between chemical composition and electronic structure was performed on the nonstoichiometric iron sulfide, mackinawite (Fe 1+x S), which is isostructural and isoelectronic with the superconducting Fe 1+x Se and Fe 1+x (Te 1-y Se y ) phases. Even though Fe 1+x S has not been measured for superconductivity, the effects of stoichiometry on transport properties and electronic structure in all of these iron-excess chalcogenide compounds has been largely overlooked. In mackinawite, the amount of Fe that has been reported ranges from a large excess, Fe 1.15 S, to nearly stoichiometric, Fe 1.00 (7) S. Here, we analyze, for the first time, the electronic structure of Fe 1+x S to justify these nonstoichiometric phases. First principles electronic structure calculations using supercells of Fe 1+x S yield a wide range of energetically favorable compositions (0 < x < 0.30). The incorporation of interstitial Fe atoms originates from a delicate balance between the Madelung energy and the occupation of Fe-S and Fe-Fe antibonding orbitals. A theoretical assessment of various magnetic structures for "FeS" and Fe 1.06 S indicate that striped magnetic ordering along [110] is the lowest energy structure and the interstitial Fe affects the values of moments in the square planes as a function of distance. Moreover, the formation of the magnetic moment is dependent on the unit cell volume, thus relating it to composition. Finally, changes in the composition cause a modification of the Fermi surface and ultimately the loss of a nested vector. ABSTRACT: A theoretical investigation of the relationship between chemical composition and electronic structure was performed on the nonstoichiometric iron sulfide, mackinawite (Fe 1+x S), which is isostructural and isoelectronic with the superconducting Fe 1+x Se and Fe 1+x (Te 1−y Se y ) phases. Even though Fe 1+x S has not been measured for superconductivity, the effects of stoichiometry on transport properties and electronic structure in all of these iron-excess chalcogenide compounds has been largely overlooked. In mackinawite, the amount of Fe that has been reported ranges from a large excess, Fe 1.15 S, to nearly stoichiometric, Fe 1.00 (7) S. Here, we analyze, for the first time, the electronic structure of Fe 1+x S to justify these nonstoichiometric phases. First principles electronic structure calculations using supercells of Fe 1+x S yield a wide range of energetically favorable compositions (0 < x < 0.30). The incorporation of interstitial Fe atoms originates from a delicate balance between the Madelung energy and the occupation of Fe−S and Fe−Fe antibonding orbitals. A theoretical assessment of various magnetic structures for "FeS" and Fe 1.06 S indicate that striped magnetic ordering along [110] is the lowest energy structure and the interstitial Fe affects the values of moments in the square planes as a function of distance. Moreover, the formation of the magnetic moment is dependent on the unit cell volume, thus relating it to...

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“…In Fe 1+x Te both magnetic (AFM) and structural (tetragonal to monoclinic) transitions occur at the same temperature T N 67 K [14], with the propagation vector aligned at 45 • from the nesting vector [17]. In the similar compound FeSe 1−y , however, only the structural transition (tetragonal to orthorhombic) occurs between 70 and 100 K and no magnetic ordering is observed at low temperature [11,12,13,18]. The structural transition in pure FeSe 1−y is reported to disappear in Fe-rich compositions, in which superconductivity is not found [13].…”

Section: Introductionmentioning

confidence: 98%

Effect of Fe excess on structural, magnetic and superconducting properties of single-crystalline Fe1+xTe1−ySey

Viennois

Giannini

Marel

et al. 2010

Journal of Solid State Chemistry

117

136

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Single crystals of Fe 1+x Te 1−y Se y have been grown with a controlled Fe excess and Se doping, and the crystal structure has been refined for various compositions. The systematic investigation of magnetic and superconducting properties as a function of the structural parameters shows how the material can be driven into various ground states, depending on doping and the structural modifications. Our results prove that the occupation of the additional Fe site, Fe2, enhances the spin localization. By reducing the excess Fe, the antiferromagnetic ordering is weakened, and the superconducting ground state is favored. We have found that both Fe excess and Se doping in synergy determine the properties of the material and an improved 3-dimensional phase diagram is proposed.

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Tetragonal-to-Orthorhombic Structural Phase Transition at 90 K in the SuperconductorFe1.01Se

Cited by 492 publications

References 21 publications

Pulsed laser deposition conditions and superconductivity of FeSe thin films

Pulsed laser deposition conditions and superconductivity of FeSe thin films

Validation of Interstitial Iron and Consequences of Nonstoichiometry in Mackinawite (Fe_1+xS)

Effect of Fe excess on structural, magnetic and superconducting properties of single-crystalline Fe1+xTe1−ySey

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Tetragonal-to-Orthorhombic Structural Phase Transition at 90 K in the SuperconductorFe1.01Se

Cited by 492 publications

References 21 publications

Pulsed laser deposition conditions and superconductivity of FeSe thin films

Pulsed laser deposition conditions and superconductivity of FeSe thin films

Validation of Interstitial Iron and Consequences of Nonstoichiometry in Mackinawite (Fe1+xS)

Effect of Fe excess on structural, magnetic and superconducting properties of single-crystalline Fe1+xTe1−ySey

Contact Info

Product

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Validation of Interstitial Iron and Consequences of Nonstoichiometry in Mackinawite (Fe_1+xS)