Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides

Opačić, M.; Lazarević, N.; Šćepanović, M.; Ryu, Hyejin; Lei, Hechang; Petrovic, C.; Popović, Z. V.

doi:10.1088/0953-8984/27/48/485701

Title: Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides

Abstract

Polarized Raman scattering spectra of superconducting K_xFe_2-ySe₂ and nonsuperconducting K_0.8Fe_1.8Co_0.2Se₂ single crystals were measured in a temperature range from 10 K up to 300 K. Two Raman active modes from the I4/mmm phase and seven from the I4/m phase are observed in frequency range from 150 to 325 cm ^-1 in both compounds, suggesting that K_0.8Fe_1.8Co_0.2Se₂ single crystal also has two-phase nature. Temperature dependence of Raman mode energy is analyzed in terms of lattice thermal expansion and phonon-phonon interaction. Temperature dependence of Raman mode linewidth is considered as temperature-induced anharmonic effects. It is shown that change of Raman mode energy with temperature is dominantly driven by thermal expansion of the crystal lattice. Abrupt change of the A_1g mode energy near T_C was observed in K_xFe_2-ySe₂ , whereas it is absent in K_0.8Fe_1.8Co_0.2Se₂. Phonon energy hardening at low temperatures in the superconducting sample is a consequence of superconductivity-induced redistribution of the electronic states below critical temperature.

Authors:

Opačić, M. ^[1]; Lazarević, N. ^[1]; Šćepanović, M. ^[1]; Ryu, Hyejin ^[2]; Lei, Hechang ^[3]; Petrovic, C. ^[2]; Popović, Z. V. ^[1]

Univ. of Belgrade, Belgrade (Serbia). Institute of Physics Belgrade
Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy
Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.

Publication Date:: Mon Nov 16 00:00:00 EST 2015

Research Org.:: Brookhaven National Laboratory (BNL), Upton, NY (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Emergent Superconductivity (CES)

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

OSTI Identifier:: 1240587

Report Number(s):: BNL-111746-2016-JA
Journal ID: ISSN 0953-8984; R&D Project: PM016; KC0201050

Grant/Contract Number:: SC00112704; Ac02-98CH10886

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Physics. Condensed Matter

Additional Journal Information:: Journal Volume: 27; Journal Issue: 48; Journal ID: ISSN 0953-8984

Publisher:: IOP Publishing

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats


                    Opačić, M., Lazarević, N., Šćepanović, M., Ryu, Hyejin, Lei, Hechang, Petrovic, C., and Popović, Z. V. Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides.  United States: N. p., 2015. 
Web.  doi:10.1088/0953-8984/27/48/485701.

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                    Opačić, M., Lazarević, N., Šćepanović, M., Ryu, Hyejin, Lei, Hechang, Petrovic, C., & Popović, Z. V. Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides.  United States.  https://doi.org/10.1088/0953-8984/27/48/485701

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                    Opačić, M., Lazarević, N., Šćepanović, M., Ryu, Hyejin, Lei, Hechang, Petrovic, C., and Popović, Z. V. Mon .  
"Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides".  United States.  https://doi.org/10.1088/0953-8984/27/48/485701.  https://www.osti.gov/servlets/purl/1240587.

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@article{osti_1240587,

  title        = {Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides},

  author       = {Opačić, M. and Lazarević, N. and Šćepanović, M. and Ryu, Hyejin and Lei, Hechang and Petrovic, C. and Popović, Z. V.},

  abstractNote = {Polarized Raman scattering spectra of superconducting KxFe2-ySe2 and nonsuperconducting K0.8Fe1.8Co0.2Se2 single crystals were measured in a temperature range from 10 K up to 300 K. Two Raman active modes from the I4/mmm phase and seven from the I4/m phase are observed in frequency range from 150 to 325 cm -1 in both compounds, suggesting that K0.8Fe1.8Co0.2Se2 single crystal also has two-phase nature. Temperature dependence of Raman mode energy is analyzed in terms of lattice thermal expansion and phonon-phonon interaction. Temperature dependence of Raman mode linewidth is considered as temperature-induced anharmonic effects. It is shown that change of Raman mode energy with temperature is dominantly driven by thermal expansion of the crystal lattice. Abrupt change of the A1g mode energy near TC was observed in KxFe2-ySe2 , whereas it is absent in K0.8Fe1.8Co0.2Se2. Phonon energy hardening at low temperatures in the superconducting sample is a consequence of superconductivity-induced redistribution of the electronic states below critical temperature.},

  doi          = {10.1088/0953-8984/27/48/485701},

  journal      = {Journal of Physics. Condensed Matter},

  number       = 48,

  volume       = 27,

  place        = {United States},

  year         = {Mon Nov 16 00:00:00 EST 2015},

  month        = {Mon Nov 16 00:00:00 EST 2015}

}

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Works referenced in this record:

Raman-scattering study of $K_{x} {Sr}_{1 - x} {Fe}_{2} {As}_{2}$ $(x = 0.0, 0.4)$
journal, August 2008

Litvinchuk, A. P.; Hadjiev, V. G.; Iliev, M. N.
Physical Review B, Vol. 78, Issue 6
DOI: 10.1103/PhysRevB.78.060503

Different response of superconductivity to the transition-metal impurities in K $_{0.8}$ Fe $_{2 - y - x} M_{x}$ Se $_{2}$ ( $M$ $=$ Cr, Mn, Co, Zn)
journal, July 2011

Tan, Dian; Zhang, Changjin; Xi, Chuanying
Physical Review B, Vol. 84, Issue 1
DOI: 10.1103/PhysRevB.84.014502

Lattice dynamics of KNi $_{2}$ Se $_{2}$
journal, April 2013

Lazarević, N.; Radonjić, M.; Šćepanović, M.
Physical Review B, Vol. 87, Issue 14
DOI: 10.1103/PhysRevB.87.144305

Evolution of precipitate morphology during heat treatment and its implications for the superconductivity in K $_{x}$ Fe $_{1.6 + y}$ Se $_{2}$ single crystals
journal, October 2012

Liu, Y.; Xing, Q.; Dennis, K. W.
Physical Review B, Vol. 86, Issue 14
DOI: 10.1103/PhysRevB.86.144507

Interplay between lattice and spin states degree of freedom in the FeSe superconductor: Dynamic spin state instabilities
journal, April 2013

Gnezdilov, Vladimir; Pashkevich, Yurii G.; Lemmens, Peter
Physical Review B, Vol. 87, Issue 14
DOI: 10.1103/PhysRevB.87.144508

Superconductivity and Magnetism in (Tl, K, Rb)Fe _x Se ₂
journal, July 2013

Fang, Minghu; Wang, Hangdong; Dong, Chiheng
Journal of Physics: Conference Series, Vol. 449
DOI: 10.1088/1742-6596/449/1/012015

Coexistence of superconductivity and antiferromagnetism in single crystals A _0.8 Fe _2−y Se ₂ (A=K, Rb, Cs, Tl/K and Tl/Rb): Evidence from magnetization and resistivity
journal, April 2011

Liu, R. H.; Luo, X. G.; Zhang, M.
EPL (Europhysics Letters), Vol. 94, Issue 2
DOI: 10.1209/0295-5075/94/27008

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

Superconductivity-induced phonon renormalization on ${NaFe}_{1 - x}$ ${Co}_{x}$ As
journal, May 2014

Um, Y. J.; Bang, Yunkyu; Min, B. H.
Physical Review B, Vol. 89, Issue 18
DOI: 10.1103/PhysRevB.89.184510

Strong and nonmonotonic temperature dependence of Hall coefficient in superconducting $K_{x} {Fe}_{2 - y} {Se}_{2}$ single crystals
journal, June 2014

Ding, Xiaxin; Pan, Yiming; Yang, Huan
Physical Review B, Vol. 89, Issue 22
DOI: 10.1103/PhysRevB.89.224515

Phonon and magnon excitations in block-antiferromagnetic K $_{0.88}$ Fe $_{1.63}$ S $_{2}$
journal, December 2011

Lazarević, N.; Lei, Hechang; Petrovic, C.
Physical Review B, Vol. 84, Issue 21
DOI: 10.1103/PhysRevB.84.214305

Giant increase in critical current density of K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ single crystals
journal, December 2011

Lei, Hechang; Petrovic, C.
Physical Review B, Vol. 84, Issue 21
DOI: 10.1103/PhysRevB.84.212502

Raman study of the temperature and magnetic-field dependence of the electronic and lattice properties of MnSi
journal, July 2014

Eiter, H. -M.; Jaschke, P.; Hackl, R.
Physical Review B, Vol. 90, Issue 2
DOI: 10.1103/PhysRevB.90.024411

Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in $A_{x} {Fe}_{2 − y} {Se}_{2}$ ( $A = K$ , Rb) Superconductors
journal, February 2013

Yi, M.; Lu, D. H.; Yu, R.
Physical Review Letters, Vol. 110, Issue 6
DOI: 10.1103/PhysRevLett.110.067003

Raman scattering study of electron-doped Pr $_{x}$ Ca $_{1 - x}$ Fe $_{2}$ As $_{2}$ superconductors
journal, September 2011

Litvinchuk, A. P.; Lv, Bing; Chu, C. W.
Physical Review B, Vol. 84, Issue 9
DOI: 10.1103/PhysRevB.84.092504

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

Lack of coupling between superconductivity and orthorhombic distortion in stoichiometric single-crystalline FeSe
journal, May 2013

Böhmer, A. E.; Hardy, F.; Eilers, F.
Physical Review B, Vol. 87, Issue 18
DOI: 10.1103/PhysRevB.87.180505

Phonons, Electrons, and Electron-Phonon Interaction: Semiconductors and High-Tc Superconductors
book, January 2002

Cardona, Manuel
NATO Science Series: B:
DOI: 10.1007/0-306-47080-2_7

Superconductivity-induced phonon self-energy effects in high-T c superconductors
journal, June 1990

Zeyher, R.; Zwicknagl, G.
Zeitschrift f�r Physik B Condensed Matter, Vol. 78, Issue 2
DOI: 10.1007/BF01307833

Influence of microstructure on superconductivity in KxFe2−ySe2 and evidence for a new parent phase K2Fe7Se8
journal, May 2013

Ding, Xiaxin; Fang, Delong; Wang, Zhenyu
Nature Communications, Vol. 4, Issue 1
DOI: 10.1038/ncomms2913

Insulating and metallic spin glass in Ni-doped $K_{x} {Fe}_{2 - y} {Se}_{2}$ single crystals
journal, May 2015

Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng
Physical Review B, Vol. 91, Issue 18
DOI: 10.1103/PhysRevB.91.184503

Superconductivity in iron compounds
journal, December 2011

Stewart, G. R.
Reviews of Modern Physics, Vol. 83, Issue 4
DOI: 10.1103/RevModPhys.83.1589

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

Spin-phonon coupling in K $_{0.8}$ Fe $_{1.6}$ Se $_{2}$ and KFe $_{2}$ Se $_{2}$ : Inelastic neutron scattering and ab initio phonon calculations
journal, May 2013

Mittal, R.; Gupta, M. K.; Chaplot, S. L.
Physical Review B, Vol. 87, Issue 18
DOI: 10.1103/PhysRevB.87.184502

Evidence for an $s$ -wave superconducting gap in K $_{x}$ Fe $_{2 - y}$ Se $_{2}$ from angle-resolved photoemission
journal, June 2012

Xu, M.; Ge, Q. Q.; Peng, R.
Physical Review B, Vol. 85, Issue 22
DOI: 10.1103/PhysRevB.85.220504

Phase separation and magnetic order in K-doped iron selenide superconductor
journal, November 2011

Li, Wei; Ding, Hao; Deng, Peng
Nature Physics, Vol. 8, Issue 2
DOI: 10.1038/nphys2155

Structural phase transition below 250 K in superconducting K $_{0.75}$ Fe $_{1.75}$ Se $_{2}$
journal, October 2012

Ignatov, A.; Kumar, A.; Lubik, P.
Physical Review B, Vol. 86, Issue 13
DOI: 10.1103/PhysRevB.86.134107

Colloquium : The unexpected properties of alkali metal iron selenide superconductors
journal, May 2013

Dagotto, Elbio
Reviews of Modern Physics, Vol. 85, Issue 2
DOI: 10.1103/RevModPhys.85.849

Vacancy ordering and phonon spectrum of the iron-based superconductor K $_{0.8}$ Fe $_{1.6}$ Se $_{2}$
journal, January 2012

Zhang, A. M.; Liu, K.; Xiao, J. H.
Physical Review B, Vol. 85, Issue 2
DOI: 10.1103/PhysRevB.85.024518

Temperature dependence of the first-order Raman scattering by phonons in Si, Ge, and $α - S n$ : Anharmonic effects
journal, February 1984

Menéndez, José; Cardona, Manuel
Physical Review B, Vol. 29, Issue 4
DOI: 10.1103/PhysRevB.29.2051

Interplay between lattice and spin states degree of freedom in the FeSe superconductor: dynamic spin state instabilities
text, January 2013

Gnezdilov, Vladimir; Pashkevich, Yurii G.; Lemmens, Peter
arXiv
DOI: 10.48550/arxiv.1301.1960

Works referencing / citing this record:

Temperature-Dependent Raman Study of Nanostructured and Multifunctional Materials
journal, March 2019

Šćepanović, Maja; Grujić-Brojčin, Mirjana; Lazarević, Nenad
physica status solidi (a), Vol. 216, Issue 13
DOI: 10.1002/pssa.201800763

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Title: Evidence of superconductivity-induced phonon spectra renormalization in alkali-doped iron selenides

Abstract

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