@article{10902/32702,
year = {2023},
month = {9},
url = {https://hdl.handle.net/10902/32702},
abstract = {BaPb₁−xBixO₃ (BPBO) bismuthate, showing high TC superconductivity for 0.05 < x < 0.35, is an archetypal system for studying the complex inhomogeneity of perovskite lattice favoring the emergence of quantum coherence, called the superstripes phase. Local lattice fluctuations, detected by EXAFS; nanoscale stripes, detected by electron microscopy; and two competing crystalline structures, detected by diffraction, are known to characterize the superconducting phase. At nanoscale [BaBiO₃] centered nanoscale units (BBO) coexist with BaBiO₃ centered (BPO) units in the BPBO perovskite; therefore, we expect a tensile microstrain in BPO units due the misfit strain between the two different lattices. Here, we report the measurement of the spatial micro-fluctuations of the local tensile microstrain ε in the BaPO units in superconducting Ba(Pb₁−xBix)O₃ crystals with x₁ = 0.19 an x₂ = 0.28. We show here the feasibility of applying the scanning dispersive micro-X-ray absorption near edge structure (SdμXANES) technique, using focused synchrotron radiation, to probe the microscale spatial fluctuations of the microstrain in BPO units. This unconventional real-space SdμXANES microscopy at the Pb L₃ edge has been collected in the dispersive mode. Our experimental method allows us to measure either the local Bi chemical concentration x and the local lattice microstrain of local BBO and BPO units. The 5 × 5 micron-size spots from the focused X-ray beam allowed us to obtain maps of 1600 points covering an area of 200 × 200 microns. The mapping shows a substantial difference between the spatial fluctuations of the microstrain ε and the chemical inhomogeneity x. Moreover, we show the different relations ε(x) in samples with lower (x₁ = 0.19) and higher (x₂ = 0.28) doping respect to the optimum doping (x = 0.25).},
organization = {This research received funding from Superstripes onlus. Supported by the National Natural Science Foundation of China (Grant No. 12075273), and work at Stanford University was supported by the U.S. Department of Energy, Office of Basic Sciences, under Contract no. DE-AC02-76SF0051.},
publisher = {MDPI},
publisher = {Condensed Matter, 2023, 8(3), 57},
title = {Tensile microstrain fluctuations in the BaPbO units in superconducting BaPb₁-xBxO₃ by scanning dispersive micro-XANES},
author = {Albertini, Ruben and Macis, Salvatore and Ivanov, Andrei A. and Menushenkov, Alexey P. and Puri, Alessandro and Monteseguro Padrón, Virginia and Joseph, Boby and Xu, Wei and Marcelli, Augusto and Giraldo-Gallo, Paula and Fisher, Ian Randal and Bianconi, Antonio and Campi, Gaetano},
}