Abstract
The topotactic reduction of La0.75Ba0.10Sr0.15FeO2.875 with titanium metal leads to a new isostructural material of the composition La0.75Ba0.10Sr0.15FeO2.875-δ (δ = 0.375 and 0.50). XRD analysis of phases confirms that the obtained compound adopts a brownmillerite-type structure. A slight distorted monoclinic P2/m was found to describe the crystal structure. The transport properties have been investigated by current–voltage (I–V). The electric and dielectric measurements were carried out covering a wide range of temperature (300–600 K). Our materials display semiconducting properties as well as mixed ionic and electronic conductivity. At high temperatures, the activation energy values proved to be around 907–630 meV, which refers basically to oxygen vacancies conduction. The analysis of dielectric properties and dielectric losses (ε’, tanδ) of both compounds vs temperature at different frequencies demonstrates two relaxer attitudes. A low dielectric loss and low electrical conductance were displayed. Relying upon these values, these materials stand for perfect candidates for micro-electronics devices.
Highlights
Much ink has been spilled upon oxygen deficient perovskite oxides owing to their multiple merits [1]
Previous studies reported [18, 19] that the brownmillerite structure with composition A2B2O5, remains ambiguous between Pnma, Imma, C2/c and I2mb space group owing to different orientations of tetrahedral chains with respect to each other
The crystallographic study demonstrated that those samples adopt the brownmillerite-type structure with no traces of secondary phase
Summary
Keywords: brownmillerite, ionic and electronic conductivity, oxygen vacancy conduction License: This work is licensed under a Creative Commons Attribution 4.0 International License. Version of Record: A version of this preprint was published at Journal of Materials Science: Materials in Electronics on August 3rd, 2021. See the published version at https://doi.org/10.1007/s10854-02106541-x.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have