Pressure-induced successive structural transitions and high-pressure tetragonal phase of Fe<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mrow><mml:mn>1.08</mml:mn></mml:mrow></mml:msub></mml:math>Te

Koz, Cevriye; Rößler, Sahana; Tsirlin, Alexander A.; Kasinathan, Deepa; Börrnert, Carina; Hanfland, M.; Rösner, H.; Wirth, S.; Schwarz, Ulrich

doi:10.1103/physrevb.86.094505

Cited by 22 publications

(30 citation statements)

References 38 publications

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“…16 with different amounts of excess iron in the range 0.02 y 0.20. Prepared samples were investigated by x-ray powder diffraction (XRD) using Co Kα 1 radiation (λ = 1.788 965Å).…”

Section: Methodsmentioning

confidence: 99%

Low-temperature phase diagram of Fe1+yTe studied using x-ray diffraction

et al. 2013

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We used low-temperature synchrotron x-ray diffraction to investigate the structural phase transitions of Fe 1+y Te in the vicinity of a tricitical point in the phase diagram. A detailed analysis of the powder diffraction patterns and temperature dependence of the peak widths in Fe 1+y Te showed that two-step structural and magnetic phase transitions occur within the compositional range 0.11 y 0.13. The phase transitions are sluggish, indicating a strong competition between the orthorhombic and the monoclinic phases. We combine high-resolution diffraction experiments with specific heat, resistivity, and magnetization measurements and present a revised temperature-composition phase diagram for Fe 1+y Te.

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“…16 with different amounts of excess iron in the range 0.02 y 0.20. Prepared samples were investigated by x-ray powder diffraction (XRD) using Co Kα 1 radiation (λ = 1.788 965Å).…”

Section: Methodsmentioning

confidence: 99%

Low-temperature phase diagram of Fe1+yTe studied using x-ray diffraction

et al. 2013

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“…Another argument is the absence of a monoclinic distortion in Fe 1+y Te above T N , which would be expected (by the same reasons as in Fe-pnictides [15]) for DDS order as the latter breaks rotational in-plane C 4 symmetry. Furthermore, for y > 0.12, magnetic transition occurs at a higher temperature than the structural transition [37]. At the same time, below the structural transition the two diagonals in the ab plane becomes inequivalent, what lowers the energy of the DDS phase.…”

mentioning

confidence: 99%

“…The data for Fe 1+y Te show that the structural transition does not occur above T N -it either happens at T N , for y < 0.12, or below T N for y > 0.12 (see Ref. [37]). The pre-emptive structural transition develops only in doped compounds Fe 1+y Te 1−x Se x [24]).…”

mentioning

confidence: 99%

Magnetism in Parent Iron Chalcogenides: Quantum Fluctuations Select Plaquette Order

2012

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We analyze magnetic order in Fe-chalcogenide Fe1+yTe -the parent compound of hightemperature superconductor Fe1+yTe1−xSex. Experiments show that magnetic order in this material contains components with momentum Q1 = (π/2, π/2) and Q2 = (π/2, −π/2) in Fe-only Brillouin zone. The actual spin order depends on the interplay between these two components. Previous works assumed that the ordered state has a single-Q (either Q1 or Q2). In such a state, spins form double stripes along one of diagonals breaking the rotational C4 symmetry. We show that quantum fluctuations actually select another order -a double Q plaquette state with equal weight of Q1 and Q2 components, which preserves C4 symmetry. We argue that the order in Fe1+yTe is determined by the competition between quantum fluctuations and magnetoelastic coupling.Introduction. The analysis of magnetism in parent compounds of iron-based superconductors (FeSCs) is an integral part of the program to understand the origin of superconductivity in these materials [1][2][3][4][5][6][7][8][9][10][11][12]. Parent compounds of Fe-pnictides are moderately correlated metals, [5,13] whose magnetic order can be reasonably well understood within itinerant scenario [7-9, 14, 16] The locations and the shapes of the Fermi surfaces (FSs) select two possible ordered state with momenta (0, π) and (π, 0)-in the Fe-only Brillouin zone (BZ) [9].In each of these two states spins are ordered in a stripe fashion -ferromagnetically along one direction in 2D Feplane and antiferromagnetically in the other. Such an order breaks C 4 lattice rotational symmetry and causes pre-emptive spin-nematic order [15]. The same magnetic order is selected in the strong coupling approach, based on J 1 − J 2 model of localized spins with nearest and second-nearest neighbor spin exchange [17,18]. The actual coupling in Fe-pnictides is neither truly small nor strong enough to cause Mott insulating behavior [13], which makes it extremely useful that the two descriptions agree.There is one family of FeSCs -11 Fe-chalcogenides Fe 1+y Te 1−x Se x , in which smooth evolution between parent and optimally doped compounds does not hold. Magnetism in these materials changes considerably between x = 0 and x ∼ 0.5, where the T c is the largest. Near optimal doping magnetic fluctuations are peaked at or near (0, π) and (π, 0), as in Fe-pnictides, while magnetic order in a parent compound Fe 1+y Te has very different momenta ±(π/2, ±π/2) [19][20][21][22][23]. Upon doping, the spectral weight at ±(π/2, ±π/2) decreases, and the spectral weight at (0, π) and (π, 0) increases [20]. The transport properties of Fe 1+y Te are also quite different from those of parent compounds of Fe-pnictides: the resistivity, ρ(T ), of Fe 1+y Te does not show a prominent increase with increasing T , but instead remains flat and even shows a small increase as T decreases [24]. ARPES studies of Fe 1+y Te show that low-energy spectra are very broad [25], consistent with the notion that electrons are not propagating. These observations lead several

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“…In order to identify the phases, Koz et al. () performed high‐pressure SXRD on Fe

_{1.08}

Te. At ambient pressure, Fe

_{1.08}

Te undergoes simultaneous first‐order structural and magnetic phase transitions, that is, from the paramagnetic tetragonal (

P 4 / italicnmm

) to the antiferromagnetic monoclinic (

P 2_{1} / m

) phase.…”

Section: Fe1+ytementioning

confidence: 99%

Synthesis, phase stability, structural, and physical properties of 11‐type iron chalcogenides

Rößler

Koz

Wirth

et al. 2016

Physica Status Solidi (b)

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This article reviews recent experimental investigations on two binary Fe-chalcogenides: FeSe and Fe1+yTe. The main focus is on synthesis, single crystal growth, chemical composition, as well as on the effect of excess iron on structural, magnetic, and transport properties of these materials. The structurally simplest Fe-based superconductor Fe1+xSe with a critical temperature Tc ≈ 8.5 K undergoes a tetragonal to orthorhombic phase transition at a temperature Ts ≈ 87 K. No longrange magnetic order is observed down to the lowest measured temperature in Fe1+xSe. On the other hand, isostructural Fe1+yTe displays a complex interplay of magnetic and structural phase transitions in dependence on the tuning parameter such as excess amount of Fe or pressure, but it becomes a superconductor only when Te is substituted by a sufficient amount of Se. We summarize experimental evidence for different competing interactions and discuss related open questions.

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Pressure-induced successive structural transitions and high-pressure tetragonal phase of Fe1.08Te

Cited by 22 publications

References 38 publications

Low-temperature phase diagram of Fe1+yTe studied using x-ray diffraction

Low-temperature phase diagram of Fe1+yTe studied using x-ray diffraction

Magnetism in Parent Iron Chalcogenides: Quantum Fluctuations Select Plaquette Order

Synthesis, phase stability, structural, and physical properties of 11‐type iron chalcogenides

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