Enhanced surface superconductivity in Ba(Fe0.95Co0.05)2As2

Parzyck, Christopher T.; Faeth, Brendan D.; Tam, Gordon N.; Stewart, Gregory R.; Shen, Kyle M.

doi:10.1063/1.5133647

Title: Enhanced surface superconductivity in Ba(Fe_0.95Co_0.05)₂As₂

Abstract

We present direct evidence for an enhanced superconducting Tc on the surface of cleaved single crystals of Ba(Fe_0.95Co_0.05)₂As₂. Transport measurements performed on samples cleaved in ultra-high vacuum show a significantly enhanced superconducting transition when compared to equivalent measurements performed in air. Deviations from the bulk resistivity appear at 21 K, well above the 10 K bulk Tc of the underdoped compound. We demonstrate that the excess conductivity above the bulk Tc can be controllably suppressed by application of potassium ions on the cleaved surface, indicating that the enhanced superconductivity is strongly localized to the sample surface. Additionally, we find that the effects of the potassium surface dosing are strongly influenced by the presence of residual gas absorbates on the sample surface, which may prevent effective charge transfer from the potassium atoms to the FeAs plane. This further supports the conclusion that the effects of the dosing (and enhanced superconductivity) are localized within a few layers of the surface.

Authors:

^[1];

^[1]; Tam, Gordon N. ^[2];

^[2];

^[1]

Cornell University, Ithaca, New York (United States). Department of Physics, Laboratory of Atomic and Solid State Physics
University of Florida, Gainesville, Florida (United States). Department of Physics

Publication Date:: Mon Feb 10 00:00:00 EST 2020

Research Org.:: Univ. of Florida, Gainesville, FL (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1800629

Alternate Identifier(s):: OSTI ID: 1599259

Grant/Contract Number:: FG02-86ER45268

Resource Type:: Accepted Manuscript

Journal Name:: Applied Physics Letters

Additional Journal Information:: Journal Volume: 116; Journal Issue: 6; Journal ID: ISSN 0003-6951

Publisher:: American Institute of Physics (AIP)

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Physics; Superconductivity; Voltmeter; Superconductors; Electrostatics; Photoelectric effect; Electron diffraction; Ultra-high vacuum; Electrical components; Adsorption

Citation Formats


                    Parzyck, Christopher T., Faeth, Brendan D., Tam, Gordon N., Stewart, Gregory R., and Shen, Kyle M. Enhanced surface superconductivity in Ba(Fe0.95Co0.05)2As2.  United States: N. p., 2020. 
Web.  doi:10.1063/1.5133647.

Copy to clipboard


                    Parzyck, Christopher T., Faeth, Brendan D., Tam, Gordon N., Stewart, Gregory R., & Shen, Kyle M. Enhanced surface superconductivity in Ba(Fe0.95Co0.05)2As2.  United States.  https://doi.org/10.1063/1.5133647

Copy to clipboard


                    Parzyck, Christopher T., Faeth, Brendan D., Tam, Gordon N., Stewart, Gregory R., and Shen, Kyle M. Mon .  
"Enhanced surface superconductivity in Ba(Fe0.95Co0.05)2As2".  United States.  https://doi.org/10.1063/1.5133647.  https://www.osti.gov/servlets/purl/1800629.

Copy to clipboard


                    
@article{osti_1800629,

  title        = {Enhanced surface superconductivity in Ba(Fe0.95Co0.05)2As2},

  author       = {Parzyck, Christopher T. and Faeth, Brendan D. and Tam, Gordon N. and Stewart, Gregory R. and Shen, Kyle M.},

  abstractNote = {We present direct evidence for an enhanced superconducting Tc on the surface of cleaved single crystals of Ba(Fe0.95Co0.05)2As2. Transport measurements performed on samples cleaved in ultra-high vacuum show a significantly enhanced superconducting transition when compared to equivalent measurements performed in air. Deviations from the bulk resistivity appear at 21 K, well above the 10 K bulk Tc of the underdoped compound. We demonstrate that the excess conductivity above the bulk Tc can be controllably suppressed by application of potassium ions on the cleaved surface, indicating that the enhanced superconductivity is strongly localized to the sample surface. Additionally, we find that the effects of the potassium surface dosing are strongly influenced by the presence of residual gas absorbates on the sample surface, which may prevent effective charge transfer from the potassium atoms to the FeAs plane. This further supports the conclusion that the effects of the dosing (and enhanced superconductivity) are localized within a few layers of the surface.},

  doi          = {10.1063/1.5133647},

  journal      = {Applied Physics Letters},

  number       = 6,

  volume       = 116,

  place        = {United States},

  year         = {Mon Feb 10 00:00:00 EST 2020},

  month        = {Mon Feb 10 00:00:00 EST 2020}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (Publisher)

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1063/1.5133647

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 1 work

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Works referenced in this record:

$\sqrt{2} \times \sqrt{2}$ structure and charge inhomogeneity at the surface of superconducting ${BaFe}_{2 - x} {Co}_{x} {As}_{2}$ $(x = 0 - 0.32)$
journal, March 2010

Zhang, Hui; Dai, Jun; Zhang, Yujing
Physical Review B, Vol. 81, Issue 10
DOI: 10.1103/PhysRevB.81.104520

Surface Geometric and Electronic Structures of ${BaFe}_{2} {As}_{2} (001)$
journal, August 2009

Nascimento, V. B.; Li, Ang; Jayasundara, Dilushan R.
Physical Review Letters, Vol. 103, Issue 7
DOI: 10.1103/PhysRevLett.103.076104

High-resolution, hard x-ray photoemission investigation of ${BaFe}_{2} {As}_{2}$ : Moderate influence of the surface and evidence for a low degree of $Fe 3 d - As 4 p$ hybridization of electronic states near the Fermi energy
journal, March 2009

de Jong, S.; Huang, Y.; Huisman, R.
Physical Review B, Vol. 79, Issue 11
DOI: 10.1103/PhysRevB.79.115125

Different effects of Ni and Co substitution on the transport properties of BaFe $_{2}$ As $_{2}$
journal, February 2011

Olariu, A.; Rullier-Albenque, F.; Colson, D.
Physical Review B, Vol. 83, Issue 5
DOI: 10.1103/PhysRevB.83.054518

Enhanced superconductivity in surface-electron-doped iron pnictide Ba(Fe1.94Co0.06)2As2
journal, August 2016

Kyung, W. S.; Huh, S. S.; Koh, Y. Y.
Nature Materials, Vol. 15, Issue 12
DOI: 10.1038/nmat4728

Surface Adatom Conductance Filtering in Scanning Tunneling Spectroscopy of Co-doped ${BaFe}_{2} {As}_{2}$ Iron Pnictide Superconductors
journal, September 2012

Koepernik, K.; Johnston, S.; van Heumen, E.
Physical Review Letters, Vol. 109, Issue 12
DOI: 10.1103/PhysRevLett.109.127001

Rashba Spin-Splitting Control at the Surface of the Topological Insulator ${Bi}_{2} {Se}_{3}$
journal, October 2011

Zhu, Z. -H.; Levy, G.; Ludbrook, B.
Physical Review Letters, Vol. 107, Issue 18
DOI: 10.1103/PhysRevLett.107.186405

Nanoscale superconducting-gap variations and lack of phase separation in optimally doped ${BaFe}_{1.86} {Co}_{0.14} {As}_{2}$
journal, June 2009

Massee, F.; Huang, Y.; Huisman, R.
Physical Review B, Vol. 79, Issue 22
DOI: 10.1103/PhysRevB.79.220517

Role of Antiferromagnetic Ordering in the ( $1 \times 2$ ) Surface Reconstruction of $Ca {({Fe}_{1 - x} {Co}_{x})}_{2} {As}_{2}$
journal, February 2014

Li, Guorong; Liang, Liangbo; Li, Qing
Physical Review Letters, Vol. 112, Issue 7
DOI: 10.1103/PhysRevLett.112.077205

Transport properties and asymmetric scattering in Ba $_{1 - x}$ K $_{x}$ Fe $_{2}$ As $_{2}$ single crystals
journal, November 2011

Shen, Bing; Yang, Huan; Wang, Zhao-Sheng
Physical Review B, Vol. 84, Issue 18
DOI: 10.1103/PhysRevB.84.184512

Bulk and surface low-energy excitations in $Y {Ba}_{2} {Cu}_{3} O_{7 - δ}$ studied by high-resolution angle-resolved photoemission spectroscopy
journal, January 2007

Nakayama, K.; Sato, T.; Terashima, K.
Physical Review B, Vol. 75, Issue 1
DOI: 10.1103/PhysRevB.75.014513

Pnictogen height as a possible switch between high- $T_{c}$ nodeless and low- $T_{c}$ nodal pairings in the iron-based superconductors
journal, June 2009

Kuroki, Kazuhiko; Usui, Hidetomo; Onari, Seiichiro
Physical Review B, Vol. 79, Issue 22
DOI: 10.1103/PhysRevB.79.224511

Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped $Ba ({Fe}_{1 - x} {Co}_{x})_{2} {As}_{2}$ Single Crystals Using Scanning Tunneling Spectroscopy
journal, February 2011

Teague, M. L.; Drayna, G. K.; Lockhart, G. P.
Physical Review Letters, Vol. 106, Issue 8
DOI: 10.1103/PhysRevLett.106.087004

Cleavage surfaces of the ${BaFe}_{2 - x} {Co}_{x} {As}_{2}$ and ${Fe}_{y} {Se}_{1 - x} {Te}_{x}$ superconductors: A combined STM plus LEED study
journal, October 2009

Massee, F.; de Jong, S.; Huang, Y.
Physical Review B, Vol. 80, Issue 14
DOI: 10.1103/PhysRevB.80.140507

High-resolution photoemission from a tunable quantum well: Cu(111)/Na
journal, July 1997

Carlsson, A.; Hellsing, B.; Lindgren, S. -Å.
Physical Review B, Vol. 56, Issue 3
DOI: 10.1103/PhysRevB.56.1593

Overlayer resonance and quantum well state of $Cs ∕ Cu (111)$ studied with angle-resolved photoemission, LEED, and first-principles calculations
journal, April 2007

Breitholtz, M.; Chis, V.; Hellsing, B.
Physical Review B, Vol. 75, Issue 15
DOI: 10.1103/PhysRevB.75.155403

Pressure versus Concentration Tuning of the Superconductivity in Ba(Fe _{1- x} Co _x ) ₂ As ₂
journal, December 2010

Drotziger, Sandra; Schweiss, Peter; Grube, Kai
Journal of the Physical Society of Japan, Vol. 79, Issue 12
DOI: 10.1143/JPSJ.79.124705

Bandwidth and Fermi surface of iron oxypnictides: Covalency and sensitivity to structural changes
journal, August 2008

Vildosola, Verónica; Pourovskii, Leonid; Arita, Ryotaro
Physical Review B, Vol. 78, Issue 6
DOI: 10.1103/PhysRevB.78.064518

Band structure and charge doping effects of the potassium-adsorbed $FeSe / {SrTiO}_{3}$ system
journal, February 2016

Zheng, Fawei; Wang, Li-Li; Xue, Qi-Kun
Physical Review B, Vol. 93, Issue 7
DOI: 10.1103/PhysRevB.93.075428

In situ doping control of the surface of high-temperature superconductors
journal, June 2008

Hossain, M. A.; Mottershead, J. D. F.; Fournier, D.
Nature Physics, Vol. 4, Issue 7
DOI: 10.1038/nphys998

Resistivity of Ba(Fe $_{1 - x}$ Co $_{x}$ ) $_{2}$ As $_{2}$ : Evidence for a broad composition range of non-Fermi-liquid behavior
journal, October 2013

Tam, G. N.; Faeth, B. D.; Kim, J. S.
Physical Review B, Vol. 88, Issue 13
DOI: 10.1103/PhysRevB.88.134503

Fermi arcs in a doped pseudospin-1/2 Heisenberg antiferromagnet
journal, June 2014

Kim, Y. K.; Krupin, O.; Denlinger, J. D.
Science, Vol. 345, Issue 6193
DOI: 10.1126/science.1251151

Observation of a d-wave gap in electron-doped Sr2IrO4
journal, October 2015

Kim, Y. K.; Sung, N. H.; Denlinger, J. D.
Nature Physics, Vol. 12, Issue 1
DOI: 10.1038/nphys3503

Superconductivity below 20 K in heavily electron-doped surface layer of FeSe bulk crystal
journal, April 2016

Seo, J. J.; Kim, B. Y.; Kim, B. S.
Nature Communications, Vol. 7, Issue 1
DOI: 10.1038/ncomms11116

Momentum and temperature dependence of renormalization effects in the high-temperature superconductor $Y {Ba}_{2} {Cu}_{3} O_{7 - δ}$
journal, August 2007

Zabolotnyy, V. B.; Borisenko, S. V.; Kordyuk, A. A.
Physical Review B, Vol. 76, Issue 6
DOI: 10.1103/PhysRevB.76.064519

Loss of nodal quasiparticle integrity in underdoped YBa2Cu3O6+x
journal, October 2010

Fournier, D.; Levy, G.; Pennec, Y.
Nature Physics, Vol. 6, Issue 11
DOI: 10.1038/nphys1763

Effects of Surface Electron Doping and Substrate on the Superconductivity of Epitaxial FeSe Films
journal, February 2016

Zhang, W. H.; Liu, X.; Wen, C. H. P.
Nano Letters, Vol. 16, Issue 3
DOI: 10.1021/acs.nanolett.5b05243

Superconductivity across Lifshitz transition and anomalous insulating state in surface K–dosed (Li _0.8 Fe _0.2 OH)FeSe
journal, July 2017

Ren, Mingqiang; Yan, Yajun; Niu, Xiaohai
Science Advances, Vol. 3, Issue 7
DOI: 10.1126/sciadv.1603238

Uniaxial versus hydrostatic pressure-induced phase transitions in CaFe $_{2}$ As $_{2}$ and BaFe $_{2}$ As $_{2}$
journal, March 2012

Tomić, Milan; Valentí, Roser; Jeschke, Harald O.
Physical Review B, Vol. 85, Issue 9
DOI: 10.1103/PhysRevB.85.094105

Surface terminations and layer-resolved tunneling spectroscopy of the 122 iron pnictide superconductors
journal, April 2019

Li, Ang; Yin, Jia-Xin; Wang, Jihui
Physical Review B, Vol. 99, Issue 13
DOI: 10.1103/PhysRevB.99.134520

Similar Records in DOE PAGES and OSTI.GOV collections:

Electrochemical synthesis of single-crystal (Ba{sub 0.05}K{sub 0.95})BiO{sub 3}{center_dot}1/6H{sub 2}O with the KSbO{sub 3} structure

Journal Article Jung, D Y ; Han, P ; Wilson, S R ; ... - Materials Research Bulletin

A new compound with a cubic structure, (Ba{sub 0.05}K{sub 0.95})BiO{sub 3}{center_dot}1/6H{sub 2}O (BKBO), was synthesized by electrochemical crystal growth using a rotating anode in molten KOH flux at 255 C. The BKBO crystal had the KSbO{sub 3} structure and belonged to space group Im{bar 3} (No 204) with Z = 12. Refinement of X-ray diffraction data at room temperature gave a = 10.0204(2) {angstrom}, V = 1006.1(1) {angstrom}{sup 3}, and R = 2.4% for 1465 unique reflections. Potassium, barium, and hydrated oxygen were found to occupy different sites in the tunnel structure. The electrical conductivity at room temperature was similarmore »« less
https://doi.org/10.1016/S0025-5408(98)00101-9
Interplay of negative electronic compressibility and capacitance enhancement in lightly-doped metal oxide Bi_0.95La_0.05FeO₃ by quantum capacitance model

Journal Article Nathabumroong, S. ; Eknapakul, T. ; Jaiban, P. ; ... - Scientific Reports

Light-sensitive capacitance variation of Bi_0.95La_0.05FeO₃ (BLFO) ceramics has been studied under violet to UV irradiation. The reversible capacitance enhancement up to 21% under 405 nm violet laser irradiation has been observed, suggesting a possible degree of freedom to dynamically control this in high dielectric materials for light-sensitive capacitance applications. By using ultraviolet photoemission spectroscopy (UPS), we show here that exposure of BLFO surfaces to UV light induces a counterintuitive shift of the O_2p valence state to lower binding energy of up to 243 meV which is a direct signature of negative electronic compressibility (NEC). A decrease of BLFO electrical resistancemore »« less
https://doi.org/10.1038/s41598-020-61859-6

Full Text Available
Magnetocaloric Effect in La{sub 0.67}Ba{sub 0.33}Mn{sub 0.95}Ni{sub 0.05}O{sub 3} Manganite Near Room Temperature

Journal Article Kharrat, N., E-mail: kharrat.noura@gmail.com ; Debbebi, I. Sfifir ; Cheikhrouhou-Koubaa, W. ; ... - Journal of Superconductivity and Novel Magnetism

We report the structural, magnetic, and magnetocaloric properties of La{sub 0.67}Ba{sub 0.33}Mn{sub 0.95}Ni{sub 0.05}O{sub 3} (LBMNO) manganite, synthesized by sol-gel method. X-ray diffraction (XRD) analysis using Rietveld refinement showed that this sample crystallizes in the rhombohedral structure with R 3-bar c space group. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analysis were used to confirm the structure formation of the LBMNO material. The temperature dependent magnetization data revealed a transition from ferromagnetic (FM) to paramagnetic (PM) phase at T{sub C}= 308 K. Using Arrott plots, it was found that the transition is of a second order. Frommore »« less
https://doi.org/10.1007/S10948-018-4816-3
Comparison of the Microstructure and Flux Pinning Properties of Polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7-d} Containing Zn{sub 0.95}Mn{sub 0.05}O or Al{sub 2}O{sub 3} Nanoparticles

Journal Article Al-Mohsin, R. A. ; Al-Otaibi, A. L. ; Almessiere, M. A. ; ... - Journal of Low Temperature Physics

Here we compare the microstructure and flux pinning properties of polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7-d} (Y-123 or YBCO) containing either Al{sub 2}O{sub 3} or Zn{sub 0.95}Mn{sub 0.05}O nanoparticles. Samples were prepared using a standard solid-state reaction process, and nanoparticles were added up to a concentration of 0.1 wt%. The crystal structure, microstructure, electrical and magnetic properties were analyzed using X-ray diffraction, scanning electron microscopy and transmission electron microscopy (TEM), and electrical resistivity and DC magnetization measurements, respectively. TEM observations showed that the addition of Zn{sub 0.95}Mn{sub 0.05}O resulted in a high density of fine twins and a variety of interacting microstructures,more »« less
https://doi.org/10.1007/S10909-018-1895-2
Piezoelectric performances of lead-reduced (1-x)(Bi{sub 0.9}La{sub 0.1})(Ga{sub 0.05}Fe{sub 0.95})O{sub 3}-x(Pb{sub 0.9}Ba{sub 0.1})TiO{sub 3} crystalline solutions in the morphotropic phase boundary

Journal Article Jinrong, Cheng ; Zhongyan, Meng ; Eric Cross, L ; ... - Journal of Applied Physics

In this investigation, (1-x)(Bi{sub 0.9}La{sub 0.1})(Ga{sub 0.05}Fe{sub 0.95})O{sub 3}-x(Pb{sub 0.9}Ba{sub 0.1})TiO{sub 3}(BLGF= -PBT) crystalline solutions have been fabricated by using the solid-state reaction method. A ferroelectric rhombohedral/tetragonal morphotropic phase boundary (MPB) of (1-x)BLGF-xPBT was observed for x=0.4. In the vicinity of MPB, 0.6BLGF-0.4PBT revealed the maximum dielectric constant K and piezoelectric d{sub 33} constant of 1168 and 186 pC/N, respectively. The substitution of 10 at. % Ba for Pb dramatically increased K and d{sub 33} of (1-x)BLGF-xPBT relative to (1-x)BLGF-xPT at the same x content. The Curie temperature T{sub c} of (1-x)BLGF-xPBT was determined to be above 386 deg. Cmore »« less
https://doi.org/10.1063/1.1810633

Similar Records

Title: Enhanced surface superconductivity in Ba(Fe0.95Co0.05)2As2

Abstract

Citation Formats

2 × 2 structure and charge inhomogeneity at the surface of superconducting BaFe 2 − x Co x As 2 ( x = 0 – 0.32 ) journal, March 2010

Surface Geometric and Electronic Structures of BaFe 2 As 2 ( 001 ) journal, August 2009

High-resolution, hard x-ray photoemission investigation of BaFe 2 As 2 : Moderate influence of the surface and evidence for a low degree of Fe 3 d – As 4 p hybridization of electronic states near the Fermi energy journal, March 2009

Different effects of Ni and Co substitution on the transport properties of BaFe 2 As 2 journal, February 2011

Enhanced superconductivity in surface-electron-doped iron pnictide Ba(Fe1.94Co0.06)2As2 journal, August 2016

Surface Adatom Conductance Filtering in Scanning Tunneling Spectroscopy of Co-doped BaFe 2 As 2 Iron Pnictide Superconductors journal, September 2012

Rashba Spin-Splitting Control at the Surface of the Topological Insulator Bi 2 Se 3 journal, October 2011

Nanoscale superconducting-gap variations and lack of phase separation in optimally doped BaFe 1.86 Co 0.14 As 2 journal, June 2009

Role of Antiferromagnetic Ordering in the ( 1 × 2 ) Surface Reconstruction of Ca ( Fe 1 − x Co x ) 2 As 2 journal, February 2014

Transport properties and asymmetric scattering in Ba 1 − x K x Fe 2 As 2 single crystals journal, November 2011

Bulk and surface low-energy excitations in Y Ba 2 Cu 3 O 7 − δ studied by high-resolution angle-resolved photoemission spectroscopy journal, January 2007

Pnictogen height as a possible switch between high- T c nodeless and low- T c nodal pairings in the iron-based superconductors journal, June 2009

Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped Ba ( Fe 1 − x Co x ) 2 As 2 Single Crystals Using Scanning Tunneling Spectroscopy journal, February 2011

Cleavage surfaces of the BaFe 2 − x Co x As 2 and Fe y Se 1 − x Te x superconductors: A combined STM plus LEED study journal, October 2009

High-resolution photoemission from a tunable quantum well: Cu(111)/Na journal, July 1997

Overlayer resonance and quantum well state of Cs ∕ Cu ( 111 ) studied with angle-resolved photoemission, LEED, and first-principles calculations journal, April 2007

Pressure versus Concentration Tuning of the Superconductivity in Ba(Fe 1- x Co x ) 2 As 2 journal, December 2010

Bandwidth and Fermi surface of iron oxypnictides: Covalency and sensitivity to structural changes journal, August 2008

Band structure and charge doping effects of the potassium-adsorbed FeSe / SrTiO 3 system journal, February 2016

In situ doping control of the surface of high-temperature superconductors journal, June 2008

Resistivity of Ba(Fe 1 − x Co x ) 2 As 2 : Evidence for a broad composition range of non-Fermi-liquid behavior journal, October 2013

Fermi arcs in a doped pseudospin-1/2 Heisenberg antiferromagnet journal, June 2014

Observation of a d-wave gap in electron-doped Sr2IrO4 journal, October 2015

Superconductivity below 20 K in heavily electron-doped surface layer of FeSe bulk crystal journal, April 2016

Momentum and temperature dependence of renormalization effects in the high-temperature superconductor Y Ba 2 Cu 3 O 7 − δ journal, August 2007

Loss of nodal quasiparticle integrity in underdoped YBa2Cu3O6+x journal, October 2010

Effects of Surface Electron Doping and Substrate on the Superconductivity of Epitaxial FeSe Films journal, February 2016

Superconductivity across Lifshitz transition and anomalous insulating state in surface K–dosed (Li 0.8 Fe 0.2 OH)FeSe journal, July 2017

Uniaxial versus hydrostatic pressure-induced phase transitions in CaFe 2 As 2 and BaFe 2 As 2 journal, March 2012

Surface terminations and layer-resolved tunneling spectroscopy of the 122 iron pnictide superconductors journal, April 2019

Title: Enhanced surface superconductivity in Ba(Fe_0.95Co_0.05)₂As₂

$\sqrt{2} \times \sqrt{2}$ structure and charge inhomogeneity at the surface of superconducting ${BaFe}_{2 - x} {Co}_{x} {As}_{2}$ $(x = 0 - 0.32)$
journal, March 2010

Surface Geometric and Electronic Structures of ${BaFe}_{2} {As}_{2} (001)$
journal, August 2009

High-resolution, hard x-ray photoemission investigation of ${BaFe}_{2} {As}_{2}$ : Moderate influence of the surface and evidence for a low degree of $Fe 3 d - As 4 p$ hybridization of electronic states near the Fermi energy
journal, March 2009

Different effects of Ni and Co substitution on the transport properties of BaFe $_{2}$ As $_{2}$
journal, February 2011

Enhanced superconductivity in surface-electron-doped iron pnictide Ba(Fe1.94Co0.06)2As2
journal, August 2016

Surface Adatom Conductance Filtering in Scanning Tunneling Spectroscopy of Co-doped ${BaFe}_{2} {As}_{2}$ Iron Pnictide Superconductors
journal, September 2012

Rashba Spin-Splitting Control at the Surface of the Topological Insulator ${Bi}_{2} {Se}_{3}$
journal, October 2011

Nanoscale superconducting-gap variations and lack of phase separation in optimally doped ${BaFe}_{1.86} {Co}_{0.14} {As}_{2}$
journal, June 2009

Role of Antiferromagnetic Ordering in the ( $1 \times 2$ ) Surface Reconstruction of $Ca {({Fe}_{1 - x} {Co}_{x})}_{2} {As}_{2}$
journal, February 2014

Transport properties and asymmetric scattering in Ba $_{1 - x}$ K $_{x}$ Fe $_{2}$ As $_{2}$ single crystals
journal, November 2011

Bulk and surface low-energy excitations in $Y {Ba}_{2} {Cu}_{3} O_{7 - δ}$ studied by high-resolution angle-resolved photoemission spectroscopy
journal, January 2007

Pnictogen height as a possible switch between high- $T_{c}$ nodeless and low- $T_{c}$ nodal pairings in the iron-based superconductors
journal, June 2009

Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped $Ba ({Fe}_{1 - x} {Co}_{x})_{2} {As}_{2}$ Single Crystals Using Scanning Tunneling Spectroscopy
journal, February 2011

Cleavage surfaces of the ${BaFe}_{2 - x} {Co}_{x} {As}_{2}$ and ${Fe}_{y} {Se}_{1 - x} {Te}_{x}$ superconductors: A combined STM plus LEED study
journal, October 2009

High-resolution photoemission from a tunable quantum well: Cu(111)/Na
journal, July 1997

Overlayer resonance and quantum well state of $Cs ∕ Cu (111)$ studied with angle-resolved photoemission, LEED, and first-principles calculations
journal, April 2007

Pressure versus Concentration Tuning of the Superconductivity in Ba(Fe _{1- x} Co _x ) ₂ As ₂
journal, December 2010

Bandwidth and Fermi surface of iron oxypnictides: Covalency and sensitivity to structural changes
journal, August 2008

Band structure and charge doping effects of the potassium-adsorbed $FeSe / {SrTiO}_{3}$ system
journal, February 2016

In situ doping control of the surface of high-temperature superconductors
journal, June 2008

Resistivity of Ba(Fe $_{1 - x}$ Co $_{x}$ ) $_{2}$ As $_{2}$ : Evidence for a broad composition range of non-Fermi-liquid behavior
journal, October 2013

Fermi arcs in a doped pseudospin-1/2 Heisenberg antiferromagnet
journal, June 2014

Observation of a d-wave gap in electron-doped Sr2IrO4
journal, October 2015

Superconductivity below 20 K in heavily electron-doped surface layer of FeSe bulk crystal
journal, April 2016

Momentum and temperature dependence of renormalization effects in the high-temperature superconductor $Y {Ba}_{2} {Cu}_{3} O_{7 - δ}$
journal, August 2007

Loss of nodal quasiparticle integrity in underdoped YBa2Cu3O6+x
journal, October 2010

Effects of Surface Electron Doping and Substrate on the Superconductivity of Epitaxial FeSe Films
journal, February 2016

Superconductivity across Lifshitz transition and anomalous insulating state in surface K–dosed (Li _0.8 Fe _0.2 OH)FeSe
journal, July 2017

Uniaxial versus hydrostatic pressure-induced phase transitions in CaFe $_{2}$ As $_{2}$ and BaFe $_{2}$ As $_{2}$
journal, March 2012

Surface terminations and layer-resolved tunneling spectroscopy of the 122 iron pnictide superconductors
journal, April 2019