Superconductivity induced by doping platinum in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>BaFe</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mtext>As</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>

Zhu, Xiaobo; Han, Fei; Mu, Gang; Cheng, Peng; Tang, Jun; Ju, Jing; Tanigaki, Katsumi; Wen, H. H.

doi:10.1103/physrevb.81.104525

Cited by 32 publications

(27 citation statements)

References 25 publications

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“…Also in all cases we found the fitted γ values to depend very weakly on the fitting range at high temperatures. The measured low-temperature γT term corresponds to the residual electronic density of states at low temperatures, and values are consistent with reports in reference [14]. The Debye temperatures obtained here are also comparable to what has been reported for similar materials [15].…”

Section: Heat Capacity Measurementssupporting

confidence: 92%

Superconductivity in Pt- and La-Doped BaFe2As2 Compounds Prepared by Solid-State Reaction

et al. 2015

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We report magnetization, resistivity and heat capacity measurements on samples of BaFe2As2, BaFe1.9Pt0.1As2 and Ba0.7La0.3Fe1.9Pt0.1As2 having been prepared by solid state reaction. Standard four-probe transport measurements in the temperature range 4.2-300 K showed that the substitution of nonisoelectronic Pt for Fe produced an electron-doped situation resulting a superconductive phase transition at Tc = 24 K. Furthermore, we observe that the coupled Spin-Density-Wave (SDW/AFM) transition which occurs for the BaFe2As2 sample at 140K as expected, occurs also in the Pt doped BaFe1.9Pt0.1As2 sample with only a small decrease in critical temperature to 138 K. We have also investigated in detail the superconducting state with magnetization measurements in the temperature range 5-400 K, up to a field of 9 T. From the magnetization data for BaFe1.9Pt0.1As2 we observe that Tc = 21.7 K, in good agreement with the resistivity measurement. The zero-field cooled (ZFC) results correspond to a large Meissner fraction. In Ba0.7La0.3Fe1.9Pt0.1As2 we also see a large diamagnetic response, with a reduction in Tc to 19.6 K. In addition, we analyzed heat capacity measurements for the electronic and phonon behavior of these materials. The analysis shows an excess entropy associated with the change in electronic behavior consistent with what is expected for Fe local moments, pointing to an electronic density of states that is based on a spin-fluctuation mechanism. We discuss the results in relation to a varying electronic density of states present in the samples, and a possible pseudogap induced by addition of Pt.Index Terms-DC magnetic susceptibility, Superconductivity, Spin density wave, Meissner effect.

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Section: Heat Capacity Measurementssupporting

confidence: 92%

Superconductivity in Pt- and La-Doped BaFe2As2 Compounds Prepared by Solid-State Reaction

et al. 2015

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“…Therefore, the superconducting phase region is extremely asymmetric as in the Pt-doped Ba-122 system. 51 The normal state is divided by the line of T min into semiconducting and metallic regions, which is similar to Co-doped and Ni-doped 1111 systems. 28,29 The most extraordinary aspect of the phase diagram is the absence of an AFM region, which exists in the underdoped side of the electronic phase diagram for all of the 1111 and 122 Fe-pnictide materials.…”

Section: Resultsmentioning

confidence: 99%

Transport properties and electronic phase diagram of single-crystallineCa10(Pt3As8)

et al. 2012

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Sizable single-crystalline samples of Ca 10 (Pt 3 As 8 )((Fe 1−x Pt x ) 2 As 2 ) 5 (the 10-3-8 phase) with 0 x < 0.1 have been grown and have been systematically characterized via x-ray diffraction, magnetic, and transport measurements. The unsubstituted sample is a heavily doped semiconductor with no sign of magnetic order down to 2 K. With increasing Pt content, the metallic behavior appears, and superconductivity is realized for x 0.023. T c rises to its maximum of approximately 13.6 K at the doping level of x ∼ 0.06 and then decreases for higher x values. The electronic phase diagram of the 10-3-8 phase was mapped out based on the magnetic and transport measurements. The mass anisotropy parameter ∼ 10, obtained from resistive measurements in magnetic fields, indicates a relatively large anisotropy in the iron-based superconductor family. This strong two-dimensional character may lead to the absence of magnetic order. A linear T dependence of susceptibility at high temperatures is observed, indicating that spin fluctuations exist in the underdoped region as in most of the Fe-pnictide superconductors.

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“…30) [for which the maximal T c at ∼23 K and ∼16 K was achieved at x = 0.05 (Ref. 29) and 0. 16 (Ref.…”

Section: Introductionmentioning

confidence: 98%

Electronic band structure, Fermi surface, and elastic properties of polymorphs of the 5.2 K iron-free superconductorSrPt2As2from first-principles calculations

Shein

Ivanovskiĭ

2011

Phys. Rev. B

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By means of first-principles calculations, we studied in detail the structural, elastic, and electronic properties of the tetragonal CaBe 2 Ge 2 -type 5.2 K superconductor SrPt 2 As 2 in comparison with two hypothetical SrPt 2 As 2 polymorphs with ThCr 2 Si 2 -type structures, which differ in the atomic configurations of the [Pt 2 As 2 ] (or [As 2 Pt 2 ]) blocks. We found that CaBe 2 Ge 2 -type SrPt 2 As 2 is a unique system with near-Fermi bands of a complicated character and an "intermediate"-type Fermi surface, which consists of electronic pockets having a cylinderlike [two-dimensional (2D)] topology (typical of 122 FeAs phases) together with 3D-like electronic and hole pockets, which are characteristic of ThCr 2 Si 2 -like iron-free low-T c superconductors. Our analysis revealed that, as distinct from ThCr 2 Si 2 -like 122 phases, other features of CaBe 2 Ge 2 -like SrPt 2 As 2 are as follows: (1) There are essential differences in the contributions from [Pt 2 As 2 ] and [As 2 Pt 2 ] blocks to the near-Fermi region; conduction is anisotropic and occurs mainly in the [Pt 2 As 2 ] blocks. (2) A 3D system of strong covalent Pt-As bonds is formed (inside and between [Pt 2 As 2 ] and [As 2 Pt 2 ] blocks), which is responsible for enhanced stability of this polymorph.(3) There is essential charge anisotropy between adjacent [Pt 2 As 2 ] and [As 2 Pt 2 ] blocks. We also predict that CaBe 2 Ge 2 -like SrPt 2 As 2 is a mechanically stable and relatively soft material with high compressibility, which will behave in a ductile manner. In contrast, the ThCr 2 Si 2 -type SrPt 2 As 2 polymorphs, which contain only [Pt 2 As 2 ] or [As 2 Pt 2 ] blocks, are less stable, have Fermi surfaces of a multisheet three-dimensional type like the ThCr 2 Si 2 -like iron-free 122 phases, and therefore will be ductile materials with high elastic anisotropy. Based on our data for the three simplest SrPt 2 As 2 polymorphs we assume that there may exist a family of higher-order polytypes, which can be formed as a result of various stackings of the two main types of building blocks ([Pt 2 As 2 ] and [As 2 Pt 2 ]) in various combinations along the z axis. This may provide an interesting platform for further theoretical and experimental search for other superconducting materials.

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Superconductivity induced by doping platinum inBaFe2As2

Cited by 32 publications

References 25 publications

Superconductivity in Pt- and La-Doped BaFe<sub>2</sub>As<sub>2</sub> Compounds Prepared by Solid-State Reaction

Superconductivity in Pt- and La-Doped BaFe<sub>2</sub>As<sub>2</sub> Compounds Prepared by Solid-State Reaction

Transport properties and electronic phase diagram of single-crystallineCa10(Pt3As8)

Electronic band structure, Fermi surface, and elastic properties of polymorphs of the 5.2 K iron-free superconductorSrPt2As2from first-principles calculations

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