Advanced synchrotron radiation focusing down to a size of 300 nm has been used to visualize nanoscale phase separation in the K0.8Fe1.6Se2 superconducting system using scanning nanofocus single-crystal x-ray diffraction. The results show an intrinsic phase separation in K0.8Fe1.6Se2 single crystals at T < 520 K, revealing the coexistence of (i) a magnetic phase characterized by an expanded lattice with superstructures due to Fe vacancy ordering and (ii) a nonmagnetic phase with an in-plane compressed lattice. The spatial distribution of the two phases at 300 K shows a frustrated or arrested nature of the phase separation. The space-resolved imaging of the phase separation permitted us to provide direct evidence of nanophase domains smaller than 300 nm and different micrometer-sized regions with percolating magnetic or nonmagnetic domains forming a multiscale complex network of the two phases.
Nanoscale phase separation in the iron chalcogenide superconductor K 0.8Fe1.6Se2 as seen via scanning nanofocused x-ray diffraction / Ricci, Alessandro; Poccia, Nicola; Campi, Gaetano; B., Joseph; G., Arrighetti; L., Barba; M., Reynolds; M., Burghammer; H., Takeya; Y., Mizuguchi; Y., Takano; Colapietro, Marcello; Saini, Naurang Lal; Bianconi, Antonio. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 84:6(2011), pp. 060511-1-060511-6. [10.1103/physrevb.84.060511]
Nanoscale phase separation in the iron chalcogenide superconductor K 0.8Fe1.6Se2 as seen via scanning nanofocused x-ray diffraction
RICCI, ALESSANDRO;POCCIA, NICOLA;CAMPI, GAETANO;COLAPIETRO, Marcello;SAINI, Naurang Lal;BIANCONI, Antonio
2011
Abstract
Advanced synchrotron radiation focusing down to a size of 300 nm has been used to visualize nanoscale phase separation in the K0.8Fe1.6Se2 superconducting system using scanning nanofocus single-crystal x-ray diffraction. The results show an intrinsic phase separation in K0.8Fe1.6Se2 single crystals at T < 520 K, revealing the coexistence of (i) a magnetic phase characterized by an expanded lattice with superstructures due to Fe vacancy ordering and (ii) a nonmagnetic phase with an in-plane compressed lattice. The spatial distribution of the two phases at 300 K shows a frustrated or arrested nature of the phase separation. The space-resolved imaging of the phase separation permitted us to provide direct evidence of nanophase domains smaller than 300 nm and different micrometer-sized regions with percolating magnetic or nonmagnetic domains forming a multiscale complex network of the two phases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.