Publication: Tensile Microstrain Fluctuations in the BaPbO Units in Superconducting BaPb1−xBixO3 by Scanning Dispersive Micro-XANES
Дата
2023
Авторы
Albertini, R.
Macis ,S.
Ivanov, A. A.
Menushenkov, A. P.
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Аннотация
BaPb1в€’xBixO3 (BPBO) bismuthate, showing high TC superconductivity for 0.05 andlt; x andlt; 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 BaPbO3 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 Оµ in the BaPO units in superconducting Ba(Pb1в€’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 (SdОјXANES) technique, using focused synchrotron radiation, to probe the microscale spatial fluctuations of the microstrain in BPO units. This unconventional real-space SdОјXANES 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 Г— 5 micron-size spots from the focused X-ray beam allowed us to obtain maps of 1600 points covering an area of 200 Г— 200 microns. The mapping shows a substantial difference between the spatial fluctuations of the microstrain Оµ and the chemical inhomogeneity x. Moreover, we show the different relations Оµ(x) in samples with lower (x1 = 0.19) and higher (x2 = 0.28) doping respect to the optimum doping (x = 0.25).
Описание
Ключевые слова
XANES , Superconductivity , Microscale chemistry
Цитирование
Tensile Microstrain Fluctuations in the BaPbO Units in Superconducting BaPb1−xBixO3 by Scanning Dispersive Micro-XANES / Albertini, R. [et al.] // Condensed Matter. - 2023. - 8. - № 3. - 10.3390/condmat8030057