title: Spectromicroscopy of electronic phase separation in KxFe2-ySe2 superconductor.
abstract: Structural phase separation in AxFe2-ySe2 system has been studied by different experimental techniques, however, it should be important to know how the electronic uniformity is influenced, on which length scale the electronic phases coexist, and what is their spatial distribution. Here, we have used novel scanning photoelectron microscopy (SPEM) to study the electronic phase separation in KxFe2-ySe2, providing a direct measurement of the topological spatial distribution of the different electronic phases. The SPEM results reveal a peculiar interconnected conducting filamentary phase that is embedded in the insulating texture. The filamentary structure with a particular topological geometry could be important for the high Tc superconductivity in the presence of a phase with a large magnetic moment in AxFe2-ySe2 materials.
authors.affiliation: Dipartimento di Fisica, Universitá di Roma "La Sapienza" - P. le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bendele
authors.affiliation: Sincrotrone Trieste S.C.p.A., Area Science Park, 34012 Basovizza, Trieste, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Barinov
authors.affiliation: Dipartimento di Fisica, Universitá di Roma "La Sapienza" - P. le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Joseph
authors.affiliation: Rome International Center for Materials Science Superstripes (RICMASS), Via dei Sabelli 119A, 00185 Roma, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Innocenti
authors.affiliation: Sincrotrone Trieste S.C.p.A., Area Science Park, 34012 Basovizza, Trieste, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Iadecola
authors.affiliation: Rome International Center for Materials Science Superstripes (RICMASS), Via dei Sabelli 119A, 00185 Roma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bianconi
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takeya
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Mizuguchi
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takano
authors.affiliation: Department of Applied Physics, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Noji
authors.affiliation: Department of Applied Physics, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hatakeda
authors.affiliation: Department of Applied Physics, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Koike
authors.affiliation: Department of Physics, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Horio
authors.affiliation: Department of Physics, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Fujimori
authors.affiliation: Department of Physics, University of Tokyo, 5-1-5 Kashiwanoha, Chiba 277-8561, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Ootsuki
authors.affiliation: 1] Department of Physics, University of Tokyo, 5-1-5 Kashiwanoha, Chiba 277-8561, Japan [2] Department of Complexity Science and Engineering, University of Tokyo, 5-1-5 Kashiwanoha, Chiba 277-8561, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mizokawa
authors.affiliation: Dipartimento di Fisica, Universitá di Roma "La Sapienza" - P. le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: N L
authors.initials: NL
authors.lastname: Saini