On the Nanoscale Structure of KxFe2-yCh2 (Ch = S, Se): A Neutron Pair Distribution Function View

Mangelis, Panagiotis; Lei, Hechang; McDonnell, Marshall; Feygenson, Mikhail; Petrovic, Cedomir; Bozin, Emil; Lappas, Alexandros

doi:10.3390/condmat3030020

Title: On the Nanoscale Structure of K_xFe_2-yCh₂ (Ch = S, Se): A Neutron Pair Distribution Function View

Abstract

Comparative exploration of the nanometer-scale atomic structure of K_xFe_2-yCh₂ (Ch = S, Se) was performed using neutron total scattering-based atomic pair distribution function (PDF) analysis of 5 K powder diffraction data in relation to physical properties. Whereas K_xFe_2-ySe₂ is a superconductor with a transition temperature of about 32 K, the isostructural sulphide analogue is not, which instead displays a spin glass semiconducting behavior at low temperatures. The PDF analysis explores phase separated and disordered structural models as candidate descriptors of the low temperature data. For both materials, the nanoscale structure is well described by the iron (Fe)-vacancy-disordered K₂Fe_5-yCh₅ (I4/m) model containing excess Fe. An equally good description of the data is achieved by using a phase separated model comprised of I4/m vacancy-ordered and I4/mmm components. The I4/mmm component appears as a minority phase in the structure of both K_xFe_2-ySe₂ and K_xFe_2-yS₂, and with similar contribution, implying that the phase ratio is not a decisive factor influencing the lack of superconductivity in the latter. Comparison of structural parameters of the Fe-vacancy-disordered model indicates that the replacement of selenium (Se) by sulphur (S) results in an appreciable reduction in the Fe-Ch interatomic distances and anion heights, while simultaneously increasing the irregularity ofmore »« less

Authors:

Mangelis, Panagiotis ^[1]; Lei, Hechang ^[2]; McDonnell, Marshall ^[3]; Feygenson, Mikhail ^[3]; Petrovic, Cedomir ^[2]; Bozin, Emil ^[2];

^[1]

Inst. of Electronic Structure and Laser (IESL), Foundation for Research and Technology- Hellas (FORTH), Vassilika Vouton, Heraklion (Greece)
Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division

Publication Date:: 2018-07-03

Research Org.:: Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1459171

Report Number(s):: BNL-206809-2018-JAAM
Journal ID: ISSN 2410-3896; TRN: US1901547

Grant/Contract Number:: SC0012704

Resource Type:: Accepted Manuscript

Journal Name:: Condensed Matter

Additional Journal Information:: Journal Volume: 3; Journal Issue: 3; Journal ID: ISSN 2410-3896

Publisher:: MDPI

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; neutron pair distribution function (PDF); intercalated iron superconductors; anion height; tetrahedron regularity

Citation Formats


                    Mangelis, Panagiotis, Lei, Hechang, McDonnell, Marshall, Feygenson, Mikhail, Petrovic, Cedomir, Bozin, Emil, and Lappas, Alexandros. On the Nanoscale Structure of KxFe2-yCh2 (Ch = S, Se): A Neutron Pair Distribution Function View.  United States: N. p., 2018. 
Web.  doi:10.3390/condmat3030020.

Copy to clipboard


                    Mangelis, Panagiotis, Lei, Hechang, McDonnell, Marshall, Feygenson, Mikhail, Petrovic, Cedomir, Bozin, Emil, & Lappas, Alexandros. On the Nanoscale Structure of KxFe2-yCh2 (Ch = S, Se): A Neutron Pair Distribution Function View.  United States.  https://doi.org/10.3390/condmat3030020

Copy to clipboard


                    Mangelis, Panagiotis, Lei, Hechang, McDonnell, Marshall, Feygenson, Mikhail, Petrovic, Cedomir, Bozin, Emil, and Lappas, Alexandros. Tue .  
"On the Nanoscale Structure of KxFe2-yCh2 (Ch = S, Se): A Neutron Pair Distribution Function View".  United States.  https://doi.org/10.3390/condmat3030020.  https://www.osti.gov/servlets/purl/1459171.

Copy to clipboard


                    
@article{osti_1459171,

  title        = {On the Nanoscale Structure of KxFe2-yCh2 (Ch = S, Se): A Neutron Pair Distribution Function View},

  author       = {Mangelis, Panagiotis and Lei, Hechang and McDonnell, Marshall and Feygenson, Mikhail and Petrovic, Cedomir and Bozin, Emil and Lappas, Alexandros},

  abstractNote = {Comparative exploration of the nanometer-scale atomic structure of KxFe2-yCh2 (Ch = S, Se) was performed using neutron total scattering-based atomic pair distribution function (PDF) analysis of 5 K powder diffraction data in relation to physical properties. Whereas KxFe2-ySe2 is a superconductor with a transition temperature of about 32 K, the isostructural sulphide analogue is not, which instead displays a spin glass semiconducting behavior at low temperatures. The PDF analysis explores phase separated and disordered structural models as candidate descriptors of the low temperature data. For both materials, the nanoscale structure is well described by the iron (Fe)-vacancy-disordered K2Fe5-yCh5 (I4/m) model containing excess Fe. An equally good description of the data is achieved by using a phase separated model comprised of I4/m vacancy-ordered and I4/mmm components. The I4/mmm component appears as a minority phase in the structure of both KxFe2-ySe2 and KxFe2-yS2, and with similar contribution, implying that the phase ratio is not a decisive factor influencing the lack of superconductivity in the latter. Comparison of structural parameters of the Fe-vacancy-disordered model indicates that the replacement of selenium (Se) by sulphur (S) results in an appreciable reduction in the Fe-Ch interatomic distances and anion heights, while simultaneously increasing the irregularity of FeCh4 tetrahedra, suggesting the more significant influence of these factors. Finally, structural features are also compared to the non-intercalated FeSe and FeS parent phases, providing further information for the discussion about the influence of the lattice degrees of freedom on the observed properties in layered iron chalcogenides.},

  doi          = {10.3390/condmat3030020},

  journal      = {Condensed Matter},

  number       = 3,

  volume       = 3,

  place        = {United States},

  year         = {2018},

  month        = {7}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.3390/condmat3030020

Other availability

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Works referenced in this record:

Structure–properties correlations in Fe chalcogenide superconductors
journal, January 2012

Malavasi, Lorenzo; Margadonna, Serena
Chemical Society Reviews, Vol. 41, Issue 10
DOI: 10.1039/c2cs35021a

PDFgetN : a user-friendly program to extract the total scattering structure factor and the pair distribution function from neutron powder diffraction data
journal, August 2000

Peterson, P. F.; Gutmann, M.; Proffen, Th.
Journal of Applied Crystallography, Vol. 33, Issue 4
DOI: 10.1107/S0021889800007123

Interface-induced superconductivity and strain-dependent spin density waves in FeSe/SrTiO3 thin films
journal, May 2013

Tan, Shiyong; Zhang, Yan; Xia, Miao
Nature Materials, Vol. 12, Issue 7
DOI: 10.1038/nmat3654

Superconductivity in the PbO-type structure -FeSe
journal, September 2008

Hsu, F. -C.; Luo, J. -Y.; Yeh, K. -W.
Proceedings of the National Academy of Sciences, Vol. 105, Issue 38
DOI: 10.1073/pnas.0807325105

Origin of the Higher- T _c Phase in the K _x Fe ₂₋ _y Se ₂ System
journal, April 2016

Tanaka, Masashi; Yanagisawa, Yusuke; Denholme, Saleem J.
Journal of the Physical Society of Japan, Vol. 85, Issue 4
DOI: 10.7566/JPSJ.85.044710

Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides
journal, September 1976

Shannon, R. D.
Acta Crystallographica Section A, Vol. 32, Issue 5, p. 751-767
DOI: 10.1107/S0567739476001551

Phase relations in K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ and the structure of superconducting K $_{x}$ Fe $_{2}$ Se $_{2}$ via high-resolution synchrotron diffraction
journal, November 2012

Shoemaker, Daniel P.; Chung, Duck Young; Claus, Helmut
Physical Review B, Vol. 86, Issue 18
DOI: 10.1103/PhysRevB.86.184511

Pressure evolution of the low-temperature crystal structure and bonding of the superconductor FeSe $(T_{c} = 37 K)$
journal, August 2009

Margadonna, S.; Takabayashi, Y.; Ohishi, Y.
Physical Review B, Vol. 80, Issue 6
DOI: 10.1103/PhysRevB.80.064506

Common Crystalline and Magnetic Structure of Superconducting $A_{2} {Fe}_{4} {Se}_{5}$ ( $A = K, Rb, Cs, Tl$ ) Single Crystals Measured Using Neutron Diffraction
journal, September 2011

Ye, F.; Chi, S.; Bao, Wei
Physical Review Letters, Vol. 107, Issue 13
DOI: 10.1103/PhysRevLett.107.137003

The Nanoscale Ordered MAterials Diffractometer NOMAD at the Spallation Neutron Source SNS
journal, September 2012

Neuefeind, Jörg; Feygenson, Mikhail; Carruth, John
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 287
DOI: 10.1016/j.nimb.2012.05.037

Superconductivity above 100 K in single-layer FeSe films on doped SrTiO3
journal, November 2014

Ge, Jian-Feng; Liu, Zhi-Long; Liu, Canhua
Nature Materials, Vol. 14, Issue 3
DOI: 10.1038/nmat4153

Investigation of the Spin-Glass Regime between the Antiferromagnetic and Superconducting Phases in Fe _{1+ y} Se _x Te _{1- x}
journal, November 2010

Katayama, Naoyuki; Ji, Sungdae; Louca, Despina
Journal of the Physical Society of Japan, Vol. 79, Issue 11
DOI: 10.1143/JPSJ.79.113702

Phase Diagram of $K_{x} {Fe}_{2 - y} {Se}_{2 - z} S_{z}$ and the Suppression of its Superconducting State by an $Fe 2 − Se / S$ Tetrahedron Distortion
journal, September 2011

Lei, Hechang; Abeykoon, Milinda; Bozin, Emil S.
Physical Review Letters, Vol. 107, Issue 13
DOI: 10.1103/PhysRevLett.107.137002

Spin-glass behavior of semiconducting $K_{x}$ Fe $_{2 - y}$ S $_{2}$
journal, May 2011

Lei, Hechang; Abeykoon, Milinda; Bozin, Emil S.
Physical Review B, Vol. 83, Issue 18
DOI: 10.1103/PhysRevB.83.180503

PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals
journal, July 2007

Farrow, C. L.; Juhas, P.; Liu, J. W.
Journal of Physics: Condensed Matter, Vol. 19, Issue 33
DOI: 10.1088/0953-8984/19/33/335219

Pressure-Induced Phase Transition in K _x Fe ₂₋ _y S ₂
journal, March 2017

Tsuchiya, Yuu; Ikeda, Shugo; Zhang, Xiao-Wei
Journal of the Physical Society of Japan, Vol. 86, Issue 3
DOI: 10.7566/JPSJ.86.033705

Superconductivity in the iron selenide $K_{x} {Fe}_{2} {Se}_{2}$ $(0 \leq x \leq 1.0)$
journal, November 2010

Guo, Jiangang; Jin, Shifeng; Wang, Gang
Physical Review B, Vol. 82, Issue 18
DOI: 10.1103/PhysRevB.82.180520

Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconducting ${FeTe}_{1 - x} {Se}_{x}$
journal, March 2016

Xu, Zhijun; Schneeloch, J. A.; Wen, Jinsheng
Physical Review B, Vol. 93, Issue 10
DOI: 10.1103/PhysRevB.93.104517

Tellurium substitution effect on superconductivity of the α-phase iron selenide
journal, October 2008

Yeh, Kuo-Wei; Huang, Tzu-Wen; Huang, Yi-lin
EPL (Europhysics Letters), Vol. 84, Issue 3
DOI: 10.1209/0295-5075/84/37002

Anion height dependence of T _c for the Fe-based superconductor
journal, April 2010

Mizuguchi, Y.; Hara, Y.; Deguchi, K.
Superconductor Science and Technology, Vol. 23, Issue 5
DOI: 10.1088/0953-2048/23/5/054013

Vacancy-induced nanoscale phase separation in K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ single crystals evidenced by Raman scattering and powder x-ray diffraction
journal, August 2012

Lazarević, N.; Abeykoon, M.; Stephens, P. W.
Physical Review B, Vol. 86, Issue 5
DOI: 10.1103/PhysRevB.86.054503

Structure and composition of the superconducting phase in alkali iron selenide $K_{y} {Fe}_{1.6 + x} {Se}_{2}$
journal, April 2014

Carr, Scott V.; Louca, Despina; Siewenie, Joan
Physical Review B, Vol. 89, Issue 13
DOI: 10.1103/PhysRevB.89.134509

The intercalation chemistry of layered iron chalcogenide superconductors
journal, October 2016

Vivanco, Hector K.; Rodriguez, Efrain E.
Journal of Solid State Chemistry, Vol. 242
DOI: 10.1016/j.jssc.2016.04.008

Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO _{1- y} (Ln = La, Nd)
journal, August 2008

Lee, Chul-Ho; Iyo, Akira; Eisaki, Hiroshi
Journal of the Physical Society of Japan, Vol. 77, Issue 8
DOI: 10.1143/JPSJ.77.083704

Superconductivity close to magnetic instability in $Fe {({Se}_{1 - x} {Te}_{x})}_{0.82}$
journal, December 2008

Fang, M. H.; Pham, H. M.; Qian, B.
Physical Review B, Vol. 78, Issue 22
DOI: 10.1103/PhysRevB.78.224503

Observation of Superconductivity in Tetragonal FeS
journal, August 2015

Lai, Xiaofang; Zhang, Hui; Wang, Yingqi
Journal of the American Chemical Society, Vol. 137, Issue 32
DOI: 10.1021/jacs.5b06687

Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd)
text, January 2008

Lee, C. H.; Iyo, A.; Eisaki, H.
arXiv
DOI: 10.48550/arxiv.0806.3821

Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide
text, January 2008

Yeh, Kuo-Wei; Huang, Tzu-Wen; Huang, Yi-Lin
arXiv
DOI: 10.48550/arxiv.0808.0474

Anion height dependence of Tc for the Fe-based superconductor
text, January 2010

Mizuguhci, Y.; Hara, Y.; Deguchi, K.
arXiv
DOI: 10.48550/arxiv.1001.1801

Works referencing / citing this record:

Correlated disorder-to-order crossover in the local structure of $K_{x} {Fe}_{2 - y} {Se}_{2 - z} S_{z}$
journal, September 2019

Mangelis, P.; Koch, R. J.; Lei, H.
Physical Review B, Vol. 100, Issue 9
DOI: 10.1103/physrevb.100.094108

Similar Records in DOE PAGES and OSTI.GOV collections:

Correlated disorder-to-order crossover in the local structure of $K_{x} {Fe}_{2 - y} {Se}_{2 - z} S_{z}$

Journal Article Mangelis, P. ; Koch, R. J. ; Lei, H. ; ... - Physical Review B

Here,more »« less
https://doi.org/10.1103/PhysRevB.100.094108

Full Text Available
Fe Vacancy Order and Domain Distribution in A{sub x}Fe{sub 2−y}Se{sub 2}

Journal Article Duan, Chunruo ; Louca, Despina - Journal of Superconductivity and Novel Magnetism

The Fe vacancy and its ordering pattern is a unique property of the A{sub x}Fe{sub 2−y}Se{sub 2} (A = K, Rb, Cs) superconductors. Below the structural transition temperature T{sub S} ∼ 550 K, the system phase separates into the I4/mmm phase with no Fe vacancy and the I4/m phase with the √5×√5×1 vacancy order. In this work, an Ising-like Hamiltonian defined on the Fe-sublattice is constructed and employed in a Metropolis Monte Carlo simulation to study the Fe vacancy order and the domain distribution under different thermal treatments. A third phase with randomly distributed Fe vacancies and space group I4/mmmmore »« less
https://doi.org/10.1007/S10948-017-4381-1
Appearance of superconductivity at the vacancy order-disorder boundary in $K_{x} {Fe}_{2 - y} {Se}_{2}$

Journal Article Duan, Chunruo ; Yang, Junjie ; Ren, Yang ; ... - Physical Review B

The role of phase separation and the effect of Fe-vacancy ordering in the emergence of superconductivity in alkali metal doped iron selenides A(x)Fe(2-y)Se(2) (A = K, Rb, Cs) is explored. High energy x-ray diffraction and Monte Carlo simulation were used to investigate the crystal structure of quenched superconducting (SC) and as-grown nonsuperconducting (NSC) KxFe2-ySe2 single crystals. The coexistence of superlattice structures with the in-plane root 2 x root 2 K-vacancy ordering and the root 5 x root 5 Fe-vacancy ordering were observed in both the SC and NSC crystals alongside the I4/mmm Fe-vacancy-free phase. Moreover, in the SC crystals, anmore »« less
Cited by 1
https://doi.org/10.1103/PhysRevB.97.184502

Full Text Available
In Situ Visualization of Local Distortions in the High-T_c Molecule-Intercalated Li_x(C₅H₅N)_yFe_2–zSe₂ Superconductor

Journal Article Berdiell, Izar Capel ; Pesko, Edyta ; Lator, Elijah ; ... - Inorganic Chemistry

A time-resolved synchrotron X-ray total scattering study sheds light on the evolution of the different structural length scales involved during the intercalation of the layered iron–selenide host by organic molecular donors, aiming at the formation of the expanded-lattice Li_x(C₅H₅N)_yFe_2–zSe₂ hybrid superconductor. The intercalates are found to crystallize in the tetragonal ThCr₂Si₂-type structure at the average level, however, with an enhanced interlayer iron–selenide spacing (d = 16.2 Å) that accommodates the heterocyclic molecular spacers. Quantitative atomic pair distribution function (PDF) analysis at variable times suggests distorted FeSe₄ tetrahedral local environments that appear swollen with respect to those in the parent β-FeSe.more »« less
https://doi.org/10.1021/acs.inorgchem.1c03610

Full Text Available
Suppression of Superconductivity and Nematic Order in Fe_1–ySe_1–xS_x (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder

Journal Article Wang, Aifeng ; Milosavljevic, Ana ; Abeykoon, A. Milinda ; ... - Inorganic Chemistry

Connections between crystal chemistry and critical temperature T_c have been in the focus of superconductivity, one of the most widely studied phenomena in physics, chemistry and materials science alike. In most Fe-based superconductors materials chemistry and physics conspire so that T_c correlates with the average anion height above the Fe plane, i.e. with the geometry of the FeAs₄ or FeCh₄ (Ch = Te, Se, S) tetrahedron. Here, by synthesizing Fe_1-ySe_1-xS_x (0 ≤ x ≤ 1, y ≤ 0.1) we find that in alloyed crystals T_c is not correlated with the anion height as most other Fe superconductors. Instead, changes inmore »« less
https://doi.org/10.1021/acs.inorgchem.2c00568

Similar Records

Title: On the Nanoscale Structure of KxFe2-yCh2 (Ch = S, Se): A Neutron Pair Distribution Function View

Abstract

Citation Formats

Structure–properties correlations in Fe chalcogenide superconductors journal, January 2012

PDFgetN : a user-friendly program to extract the total scattering structure factor and the pair distribution function from neutron powder diffraction data journal, August 2000

Interface-induced superconductivity and strain-dependent spin density waves in FeSe/SrTiO3 thin films journal, May 2013

Superconductivity in the PbO-type structure -FeSe journal, September 2008

Origin of the Higher- T c Phase in the K x Fe 2− y Se 2 System journal, April 2016

Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides journal, September 1976

Phase relations in K x Fe 2 − y Se 2 and the structure of superconducting K x Fe 2 Se 2 via high-resolution synchrotron diffraction journal, November 2012

Pressure evolution of the low-temperature crystal structure and bonding of the superconductor FeSe ( T c = 37 K ) journal, August 2009

Common Crystalline and Magnetic Structure of Superconducting A 2 Fe 4 Se 5 ( A = K , Rb , Cs , Tl ) Single Crystals Measured Using Neutron Diffraction journal, September 2011

The Nanoscale Ordered MAterials Diffractometer NOMAD at the Spallation Neutron Source SNS journal, September 2012

Superconductivity above 100 K in single-layer FeSe films on doped SrTiO3 journal, November 2014

Investigation of the Spin-Glass Regime between the Antiferromagnetic and Superconducting Phases in Fe 1+ y Se x Te 1- x journal, November 2010

Phase Diagram of K x Fe 2 − y Se 2 − z S z and the Suppression of its Superconducting State by an Fe 2 − Se / S Tetrahedron Distortion journal, September 2011

Spin-glass behavior of semiconducting K x Fe 2 − y S 2 journal, May 2011

PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals journal, July 2007

Pressure-Induced Phase Transition in K x Fe 2− y S 2 journal, March 2017

Superconductivity in the iron selenide K x Fe 2 Se 2 ( 0 ≤ x ≤ 1.0 ) journal, November 2010

Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconducting FeTe 1 − x Se x journal, March 2016

Tellurium substitution effect on superconductivity of the α-phase iron selenide journal, October 2008

Anion height dependence of T c for the Fe-based superconductor journal, April 2010

Vacancy-induced nanoscale phase separation in K x Fe 2 − y Se 2 single crystals evidenced by Raman scattering and powder x-ray diffraction journal, August 2012

Structure and composition of the superconducting phase in alkali iron selenide K y Fe 1.6 + x Se 2 journal, April 2014

The intercalation chemistry of layered iron chalcogenide superconductors journal, October 2016

Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO 1- y (Ln = La, Nd) journal, August 2008

Superconductivity close to magnetic instability in Fe ( Se 1 − x Te x ) 0.82 journal, December 2008

Observation of Superconductivity in Tetragonal FeS journal, August 2015

Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd) text, January 2008

Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide text, January 2008

Anion height dependence of Tc for the Fe-based superconductor text, January 2010

Correlated disorder-to-order crossover in the local structure of K x Fe 2 − y Se 2 − z S z journal, September 2019

Title: On the Nanoscale Structure of K_xFe_2-yCh₂ (Ch = S, Se): A Neutron Pair Distribution Function View

Structure–properties correlations in Fe chalcogenide superconductors
journal, January 2012

PDFgetN : a user-friendly program to extract the total scattering structure factor and the pair distribution function from neutron powder diffraction data
journal, August 2000

Interface-induced superconductivity and strain-dependent spin density waves in FeSe/SrTiO3 thin films
journal, May 2013

Superconductivity in the PbO-type structure -FeSe
journal, September 2008

Origin of the Higher- T _c Phase in the K _x Fe ₂₋ _y Se ₂ System
journal, April 2016

Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides
journal, September 1976

Phase relations in K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ and the structure of superconducting K $_{x}$ Fe $_{2}$ Se $_{2}$ via high-resolution synchrotron diffraction
journal, November 2012

Pressure evolution of the low-temperature crystal structure and bonding of the superconductor FeSe $(T_{c} = 37 K)$
journal, August 2009

Common Crystalline and Magnetic Structure of Superconducting $A_{2} {Fe}_{4} {Se}_{5}$ ( $A = K, Rb, Cs, Tl$ ) Single Crystals Measured Using Neutron Diffraction
journal, September 2011

The Nanoscale Ordered MAterials Diffractometer NOMAD at the Spallation Neutron Source SNS
journal, September 2012

Superconductivity above 100 K in single-layer FeSe films on doped SrTiO3
journal, November 2014

Investigation of the Spin-Glass Regime between the Antiferromagnetic and Superconducting Phases in Fe _{1+ y} Se _x Te _{1- x}
journal, November 2010

Phase Diagram of $K_{x} {Fe}_{2 - y} {Se}_{2 - z} S_{z}$ and the Suppression of its Superconducting State by an $Fe 2 − Se / S$ Tetrahedron Distortion
journal, September 2011

Spin-glass behavior of semiconducting $K_{x}$ Fe $_{2 - y}$ S $_{2}$
journal, May 2011

PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals
journal, July 2007

Pressure-Induced Phase Transition in K _x Fe ₂₋ _y S ₂
journal, March 2017

Superconductivity in the iron selenide $K_{x} {Fe}_{2} {Se}_{2}$ $(0 \leq x \leq 1.0)$
journal, November 2010

Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconducting ${FeTe}_{1 - x} {Se}_{x}$
journal, March 2016

Tellurium substitution effect on superconductivity of the α-phase iron selenide
journal, October 2008

Anion height dependence of T _c for the Fe-based superconductor
journal, April 2010

Vacancy-induced nanoscale phase separation in K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ single crystals evidenced by Raman scattering and powder x-ray diffraction
journal, August 2012

Structure and composition of the superconducting phase in alkali iron selenide $K_{y} {Fe}_{1.6 + x} {Se}_{2}$
journal, April 2014

The intercalation chemistry of layered iron chalcogenide superconductors
journal, October 2016

Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO _{1- y} (Ln = La, Nd)
journal, August 2008

Superconductivity close to magnetic instability in $Fe {({Se}_{1 - x} {Te}_{x})}_{0.82}$
journal, December 2008

Observation of Superconductivity in Tetragonal FeS
journal, August 2015

Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd)
text, January 2008

Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide
text, January 2008

Anion height dependence of Tc for the Fe-based superconductor
text, January 2010

Correlated disorder-to-order crossover in the local structure of $K_{x} {Fe}_{2 - y} {Se}_{2 - z} S_{z}$
journal, September 2019