Correlation of Electrical Response and Structural Phase Transitions in Bi2O3 Nanowires. Issue 19 (20th June 2018)

• Record Type: Journal Article
• Authors: Vila, María; Rivera‐Calzada, Alberto; Salas‐Colera, Eduardo; Castro, Germán R.; Díaz‐Guerra, Carlos
• Other Names: Méndez Bianchi guestEditor.; Cremades Ana guestEditor.; Fernández Paloma guestEditor.
• Is Part Of: Physica status solidi. Volume 215:Issue 19(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-06-20
• Subjects: ionic transport -- nanostructured materials -- oxide semiconductors -- X‐ray absorption -- X‐ray diffraction; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201800186
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : The electric response of Bi2 O3 nanowires is studied by means of impedance spectroscopy at high temperatures and compared to a reference bulk Bi2 O3 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. Abstract : The ionic transport properties of Bi2 O3 nanowires and ceramics as a function of temperature are investigated and correlated with a structural study of the samples. An α → δ phase transition is observed in both materials, but a direct δ → α transition, without the formation of metastable phases, is observed on cooling the nanowires, probably due to their lower thermal conductivity.