Multiscale distribution of oxygen puddles in 1/8 doped YBa2Cu3O6.67.
Despite intensive research a physical explanation of high Tc superconductors remains elusive. One reason for this is that these materials have generally a very complex structure making useless theoretical models for a homogeneous system. Little is known on the control of the critical temperature by the space disposition of defects because of lack of suitable experimental probes. X-ray diffraction and neutron scattering experiments used to investigate y oxygen dopants in YBa2Cu3O6+y lack of spatial resolution. Here we report the spatial imaging of dopants distribution inhomogeneity in YBa2Cu3O6.67 using scanning nano X-ray diffraction. By changing the X-ray beam size from 1 micron to 300 nm of diameter, the lattice inhomogeneity increases. The ordered oxygen puddles size distribution vary between 6-8 nm using 1 × 1 μm(2) beam, while it is between 5-12 nm with a fat tail using the 300 × 300 nm(2) beam. The increased inhomogeneity at the nanoscale points toward a network of superconducting puddles made of ordered oxygen interstitials.
Deutsches Elektronen-Synchrotron DESY, Notkestraβe 85, D-22607 Hamburg, Germany.
Alessandro
A
Ricci
Nicola
N
Poccia
Gaetano
G
Campi
Francesco
F
Coneri
Alessandra Stella
AS
Caporale
Davide
D
Innocenti
Manfred
M
Burghammer
Martin V
MV
Zimmermann
Antonio
A
Bianconi
D003300:Copper / Q000737:chemistry*; D004553:Electric Conductivity; D008422:Materials Testing; D010100:Oxygen / Q000737:chemistry*
D003300:Copper; D010100:Oxygen; C000520:cuprous oxide