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Correlation of Electrical Response and Structural Phase Transitions in Bi 2 O 3 Nanowires
Author(s) -
Vila María,
RiveraCalzada Alberto,
SalasColera Eduardo,
Castro Germán R.,
DíazGuerra Carlos
Publication year - 2018
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201800186
Subject(s) - nanowire , materials science , phase transition , dielectric spectroscopy , atmospheric temperature range , x ray absorption spectroscopy , phase (matter) , ceramic , electrical resistivity and conductivity , diffraction , analytical chemistry (journal) , spectroscopy , absorption spectroscopy , condensed matter physics , nanotechnology , chemistry , thermodynamics , optics , electrochemistry , physics , composite material , organic chemistry , electrode , quantum mechanics , chromatography
The electric response of Bi 2 O 3 nanowires is studied by means of impedance spectroscopy at high temperatures and compared to a reference bulk Bi 2 O 3 ceramic. Nanowires present the α to δ phase transition at a similar temperature than the ceramic (1007 vs. 1010 K), showing an increase of over two orders of magnitude in the conductance. On cooling, nanowires change directly to the α phase instead of presenting metastable phases, like the bulk sample. Both samples present a dominant ionic contribution in the δ phase which is also present in the α phase at the highest temperatures. X‐ray absorption spectroscopy (XAS) measurements reveal no differences in the short range structural order of both kinds of samples at room temperature, while a detailed analysis by high temperature X‐ray diffraction (HTXRD) confirms the transitions observed in the conductance measurements. The authors relate the direct phase transition δ → α in nanowires to a lower thermal conductivity in these nanostructures.