3D visualizations of nanoscale phase separation and ultrafast dynamic correlation between phases in (Na0.32 K0.68) 0.95 Fe1.75 Se2

P. C. Cheng; W. Y. Tzeng; Y. J. Chu; C. W. Luo; Alexander Zhukov; John Whittaker; J.-Y. Lin; K. H. Wu; J. Y. Juang; M.  Liu; I. V. Morozov; A. I. Boltalin; A. N. Vasiliev

doi:10.1103/physrevmaterials.3.034802

3D visualizations of nanoscale phase separation and ultrafast dynamic correlation between phases in (Na0.32 K0.68) 0.95 Fe1.75 Se2

P. C. Cheng, W. Y. Tzeng, Y. J. Chu, C. W. Luo, Alexander Zhukov, John Whittaker, J.-Y. Lin, K. H. Wu, J. Y. Juang, M. Liu, I. V. Morozov, A. I. Boltalin, A. N. Vasiliev

Research output: Contribution to journal › Article › peer-review

Abstract

Phase separation of metallic and antiferromagnetic (AFM) insulating phases in alkaline iron selenides (AxFe2−ySe2 ) continues to attract intense interest because the relationship between two peculiar features probably is a key to clarifying the pairing mechanism of AxFe2−ySe2 superconductors. Here we report that the three-dimensional (3D) visualizations of nanoscale phase separation in (Na0.32K0.68 )0.95Fe1.75Se2 single crystals are revealed by hybrid focused-ion-beam scanning electron microscopy and the superconducting paths are fully percolative in 3D. Moreover, the phase-related ultrafast dynamics in (Na0.32K0.68 )0.95Fe1.75Se2 is studied by dual-color pump-probe spectroscopy. The anomalous changes in the electron and acoustic phonon components of transient reflectivity change (ΔR/R) identify two characteristic temperatures T ∗ ∼ 100K (the onset temperature of coupling between the nanometallic and AFM phases) and TH ∼ 230K (the onset temperature of the metallicinterface phase). An energy-transfer channel between the nanometallic and AFM phases is inferred. This proposed channel provides insight into the pairing mechanism of alkaline iron selenide superconductors.

Original language	English
Journal	Physical Review Materials
Early online date	25 Mar 2019
DOIs	https://doi.org/10.1103/physrevmaterials.3.034802
Publication status	Published - 2019

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https://journals.aps.org/prmaterials/pdf/10.1103/PhysRevMaterials.3.034802

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Cheng, P. C., Tzeng, W. Y., Chu, Y. J., Luo, C. W., Zhukov, A., Whittaker, J., Lin, J.-Y., Wu, K. H., Juang, J. Y., Liu, M., Morozov, I. V., Boltalin, A. I., & Vasiliev, A. N. (2019). 3D visualizations of nanoscale phase separation and ultrafast dynamic correlation between phases in (Na0.32 K0.68) 0.95 Fe1.75 Se2. Physical Review Materials. https://doi.org/10.1103/physrevmaterials.3.034802

@article{743fcdf324834a49b9a9ccf885588d7b,

title = "3D visualizations of nanoscale phase separation and ultrafast dynamic correlation between phases in (Na0.32 K0.68) 0.95 Fe1.75 Se2",

abstract = "Phase separation of metallic and antiferromagnetic (AFM) insulating phases in alkaline iron selenides (AxFe2−ySe2 ) continues to attract intense interest because the relationship between two peculiar features probably is a key to clarifying the pairing mechanism of AxFe2−ySe2 superconductors. Here we report that the three-dimensional (3D) visualizations of nanoscale phase separation in (Na0.32K0.68 )0.95Fe1.75Se2 single crystals are revealed by hybrid focused-ion-beam scanning electron microscopy and the superconducting paths are fully percolative in 3D. Moreover, the phase-related ultrafast dynamics in (Na0.32K0.68 )0.95Fe1.75Se2 is studied by dual-color pump-probe spectroscopy. The anomalous changes in the electron and acoustic phonon components of transient reflectivity change (ΔR/R) identify two characteristic temperatures T ∗ ∼ 100K (the onset temperature of coupling between the nanometallic and AFM phases) and TH ∼ 230K (the onset temperature of the metallicinterface phase). An energy-transfer channel between the nanometallic and AFM phases is inferred. This proposed channel provides insight into the pairing mechanism of alkaline iron selenide superconductors.",

author = "Cheng, {P. C.} and Tzeng, {W. Y.} and Chu, {Y. J.} and Luo, {C. W.} and Alexander Zhukov and John Whittaker and J.-Y. Lin and Wu, {K. H.} and Juang, {J. Y.} and M. Liu and Morozov, {I. V.} and Boltalin, {A. I.} and Vasiliev, {A. N.}",

year = "2019",

doi = "10.1103/physrevmaterials.3.034802",

language = "English",

journal = "Physical Review Materials",

issn = "2475-9953",

publisher = "APS Publishing",

}

TY - JOUR

T1 - 3D visualizations of nanoscale phase separation and ultrafast dynamic correlation between phases in (Na0.32 K0.68) 0.95 Fe1.75 Se2

AU - Cheng, P. C.

AU - Tzeng, W. Y.

AU - Chu, Y. J.

AU - Luo, C. W.

AU - Zhukov, Alexander

AU - Whittaker, John

AU - Lin, J.-Y.

AU - Wu, K. H.

AU - Juang, J. Y.

AU - Liu, M.

AU - Morozov, I. V.

AU - Boltalin, A. I.

AU - Vasiliev, A. N.

PY - 2019

Y1 - 2019

N2 - Phase separation of metallic and antiferromagnetic (AFM) insulating phases in alkaline iron selenides (AxFe2−ySe2 ) continues to attract intense interest because the relationship between two peculiar features probably is a key to clarifying the pairing mechanism of AxFe2−ySe2 superconductors. Here we report that the three-dimensional (3D) visualizations of nanoscale phase separation in (Na0.32K0.68 )0.95Fe1.75Se2 single crystals are revealed by hybrid focused-ion-beam scanning electron microscopy and the superconducting paths are fully percolative in 3D. Moreover, the phase-related ultrafast dynamics in (Na0.32K0.68 )0.95Fe1.75Se2 is studied by dual-color pump-probe spectroscopy. The anomalous changes in the electron and acoustic phonon components of transient reflectivity change (ΔR/R) identify two characteristic temperatures T ∗ ∼ 100K (the onset temperature of coupling between the nanometallic and AFM phases) and TH ∼ 230K (the onset temperature of the metallicinterface phase). An energy-transfer channel between the nanometallic and AFM phases is inferred. This proposed channel provides insight into the pairing mechanism of alkaline iron selenide superconductors.

AB - Phase separation of metallic and antiferromagnetic (AFM) insulating phases in alkaline iron selenides (AxFe2−ySe2 ) continues to attract intense interest because the relationship between two peculiar features probably is a key to clarifying the pairing mechanism of AxFe2−ySe2 superconductors. Here we report that the three-dimensional (3D) visualizations of nanoscale phase separation in (Na0.32K0.68 )0.95Fe1.75Se2 single crystals are revealed by hybrid focused-ion-beam scanning electron microscopy and the superconducting paths are fully percolative in 3D. Moreover, the phase-related ultrafast dynamics in (Na0.32K0.68 )0.95Fe1.75Se2 is studied by dual-color pump-probe spectroscopy. The anomalous changes in the electron and acoustic phonon components of transient reflectivity change (ΔR/R) identify two characteristic temperatures T ∗ ∼ 100K (the onset temperature of coupling between the nanometallic and AFM phases) and TH ∼ 230K (the onset temperature of the metallicinterface phase). An energy-transfer channel between the nanometallic and AFM phases is inferred. This proposed channel provides insight into the pairing mechanism of alkaline iron selenide superconductors.

U2 - 10.1103/physrevmaterials.3.034802

DO - 10.1103/physrevmaterials.3.034802

M3 - Article

SN - 2475-9953

JO - Physical Review Materials

JF - Physical Review Materials

ER -

3D visualizations of nanoscale phase separation and ultrafast dynamic correlation between phases in (Na0.32 K0.68) 0.95 Fe1.75 Se2

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