Stacking Variants and Superconductivity in the Bi–O–S System

Phelan, W. Adam; Wallace, David C.; Arpino, Kathryn E.; Neilson, James R.; Livi, Kenneth J. T.; Seabourne, Che R.; Scott, A. J.; McQueen, Tyrel M.

doi:10.1021/ja4011767

Cited by 82 publications

(106 citation statements)

References 17 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…LaOBiS2, were seen [9]. Such disorder has also been seen in Bi4O4S3 and related compounds [35,36]. Although clear diffraction peaks of LaOBiS2 were not seen in the XRD pattern, TEM diffraction suggests that the exact structure of La2O2Bi3AgS6 is rather complicated, and the above Rietveld analysis can thus derive the average structure without considering the local disorder.…”

Section: Resultsmentioning

confidence: 93%

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La₂O₂Bi₃AgS₆

et al. 2017

View full text Add to dashboard Cite

We have synthesized a new layered oxychalcogenide La2O2Bi3AgS6. From synchrotron X-ray diffraction and Rietveld refinement, the crystal structure of La2O2Bi3AgS6 was refined using a model of the P4/nmm space group with a = 4.0644(1) Å and c = 19.412(1) Å, which is similar to the related compound LaOBiPbS3, while the interlayer bonds (M2-S1 bonds) are apparently shorter in La2O2Bi3AgS6. The tunneling electron microscopy (TEM) image confirmed the lattice constant derived from Rietveld refinement (c ~ 20 Å). The electrical resistivity and Seebeck coefficient suggested that the electronic states of La2O2Bi3AgS6 are more metallic than those of LaOBiS2 and LaOBiPbS3. The insertion of a rock-salt-type chalcogenide into the van der Waals gap of BiS2-based layered compounds, such as LaOBiS2, will be a useful strategy for designing new layered functional materials in the layered chalcogenide family.

show abstract

Section: Resultsmentioning

confidence: 93%

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La₂O₂Bi₃AgS₆

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Following LaOBiS 2 , many compounds having similar structure are reported for the purpose of exploring the BiS 2 -based superconductivity 7,10 Figure 4(b) shows the relative energy of the polytypes of these materials.…”

Section: Pressure-induced Phase Transition and Polytypes In Other mentioning

confidence: 99%

“…LaOBiS 2 -type materials have drawn attention because of the measured superconductivity [1][2][3][4][5][6][7][8][9][10][11][12][13][14] (up to T c = 10.6 K) and because the BiS 2 layer is spin-orbit active and thus leads to many interesting spin-related properties, including hidden spin polarization 15 , spin field effect transistor 16 and electrically tunable Dirac cones 17 18 . Many materials described by this structural scheme have recently been synthesized 1, 2, 4, 5, 7, 9, 10, 14 , and even more members not listed in inorganic compound data bases (ICSD) can be conceived 17,19 .…”

Section: Introductionmentioning

confidence: 99%

Polytypism inLaOBiS2-type compounds based on different three-dimensional stacking sequences of two-dimensionalBiS2layers

2016

View full text Add to dashboard Cite

LaOBiS 2 -type materials have drawn much attention recently because of various interesting physical properties, such as low-temperature superconductivity, hidden spin polarization, and electrically tunable Dirac cones. However, it was generally assumed that each LaOBiS 2 -type compound has a unique and specific crystallographic structure (with a space group P4/nmm) separated from other phases. Using first-principles total energy and stability calculations we confirm that the previous assignment of the centrosymetric P4/nmm structure to LaOBiS 2 is incorrect as a phonon instability renders this structure impossible. Furthermore, we find that the unstable structure is replaced by a family of energetically closely spaced modifications (polytypes) differing by the layer sequences and orientations. We find that the local Bi-S distortion leads to three polytypes of LaOBiS 2 with different stacking patterns of the distorted BiS 2 layers. The energy difference between the polytypes of LaOBiS2 is merely ~1 meV/u.c., indicating the possible coexistence of all polytypes in the real sample and that the particular distribution of polytypes may be growth-induced. The in-plane distortion can be suppressed by pressure, leading to a phase transition from polytypes to the high-symmetry P4/nmm structure with a pressure larger than 2.5 GPa. In addition, different choices of the intermediate atoms (replacing La) or active atoms (BiS 2 ) could also manifest different ground state structures. One can thus tune the distortion and the ground state by pressure or substituting covalence atoms in LaOBiS 2 -family.2

show abstract

“…The superconductivity has been proved by many other groups 3-10 . Since the previous experiments were all done on polycrystalline samples, therefore there remains a concern whether the superconductivity is really derived from the materials intrinsically or from some secondary phases 11 . Experiments on single crystals are highly desired.…”

mentioning

confidence: 99%

Giant superconducting fluctuation and anomalous semiconducting normal state in NdO _1−x F _x Bi _1−y S ₂ single crystals

Liu¹,

Fang²,

Wang³

et al. 2014

EPL

View full text Add to dashboard Cite

The BiS 2 -based superconductors were discovered recently 1-2 . The superconductivity has been proved by many other groups 3-10 . Since the previous experiments were all done on polycrystalline samples, therefore there remains a concern whether the superconductivity is really derived from the materials intrinsically or from some secondary phases 11 . Experiments on single crystals are highly desired. In this paper, we report the successful growth of the In the Bardeen-Cooper-Schrieffer (BCS) theory, the electron pairing and condensation occur simultaneously at T c . The superconducting fluctuation may extend to above T c in a very narrow region (less than 10% T c ) 12 . Therefore it is a surprise that the superconducting fluctuation appears at temperatures far above T c in the cuprates [13][14][15][16] . In some thin but dirty metallic films, people were pursuing a man-made wide superconducting fluctuation region in terms of the Cooper pair gas state [17][18] . In addition, in the BCS scheme, the normal state after the superconductivity is suppressed should show a metallic behavior. Any semiconducting or insulating behavior appearing in the normal state should have its special reasons. Within the weak electron-phonon coupling BCS picture, one has=3.5 with ∆ s the superconducting gap. This ratio can be slightly higher in the conventional superconductors with strong coupling, but can reach about 8 in the cuprates 19 . In this paper we will show that 3 all three features mentioned above for the BCS scheme will be violated in the newly discovered superconductor NdO 1-x F x Bi 1-y S 2 single crystal samples.The single crystals NdO 1-x F x Bi 1-y S 2 were grown using flux method with KCl/LiCl as the flux. The details about the sample growth are given in Methods. The crystals are very shiny with the dark-grey color. In Fig.1b, we show the Laue diffraction pattern on one crystal. The clear and symmetric spots can be well fitted to the model calculations of crystallography, indicating high quality of the crystals. From the data of Laue diffraction pattern, we can determine the in-plane crystalline axes, which is very helpful for the precise in-plane resistive measurements. In Fig.1c, we show the X-ray diffraction (XRD) patterns for the samples grown with different nominal concentrations of fluorine. It is clear that only (00l) reflections can be observed yielding a c-axis lattice constant c = 13.49±0.04 Å. In Fig.1d, we show a picture of one crystal on which the composition is analyzed using the energy-dispersion-spectrum (EDS). From the EDS data, one can see that our crystal has a formula like NdO 1-x F x Bi 0.84 S 1.94 . Since the oxygen and fluorine are both light elements, the value given here about them are not reliable, although the nominal compositions of them are well documented. We found that the samples with the nominal fluorine concentration less than 30% are not or bad superconductive. Due to the error bars of the EDS measurements, we can conclude that the composition of sulfur here is close to 2, but Bi is ...

show abstract

Stacking Variants and Superconductivity in the Bi–O–S System

Cited by 82 publications

References 17 publications

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La₂O₂Bi₃AgS₆

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La₂O₂Bi₃AgS₆

Polytypism inLaOBiS2-type compounds based on different three-dimensional stacking sequences of two-dimensionalBiS2layers

Giant superconducting fluctuation and anomalous semiconducting normal state in NdO _1−x F _x Bi _1−y S ₂ single crystals

Contact Info

Product

Resources

About

Stacking Variants and Superconductivity in the Bi–O–S System

Cited by 82 publications

References 17 publications

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La2O2Bi3AgS6

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La2O2Bi3AgS6

Polytypism inLaOBiS2-type compounds based on different three-dimensional stacking sequences of two-dimensionalBiS2layers

Giant superconducting fluctuation and anomalous semiconducting normal state in NdO 1−x F x Bi 1−y S 2 single crystals

Contact Info

Product

Resources

About

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La₂O₂Bi₃AgS₆

Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La₂O₂Bi₃AgS₆

Giant superconducting fluctuation and anomalous semiconducting normal state in NdO _1−x F _x Bi _1−y S ₂ single crystals