Thermally stable negative permittivity and fano like resonance in multi-doped manganite
Year: 2025
Type: article
Abstract: We report an atypical dielectric behavior of a newly synthesized A-site multi-doped La 0.4 Bi 0.3 Sr 0.2 Ba 0.1 MnO 3 manganite, which has not been reported previously. The material exhibits a thermally robust negative real permittivity across a broad frequency (10KHz-100MHz) and temperature range (230K–400K). This is interpreted as result of a collective plasmonic state of free electrons and modeled according to the Drude formalism. Dielectric losses exhibit exceptionally low values and tanδ reaches notable minima (0.0002<tanδ<0.01). A striking feature is a double zero-crossing of real permittivity around 40MHz which emerges from the interplay between slow interfacial polarization and fast grain response. This previously unreported phenomenon , in single-phase manganites, suggests a Fano-Like resonance modeled according to the Lorentz-Drude formalism. Furthermore, the imaginary permittivity exhibits negative values at high frequencies, a phenomenon rarely observed in natural materials. These combined phenomena, unprecedented in this material class, position La 0.4 Bi 0.3 Sr 0.2 Ba 0.1 MnO 3 as a unique functional oxide with high potential for applications in metamaterials, near-zero permittivity structures, and electromagnetic wave modulators.
Source: Materials Today Physics
Authors: H. Salhi, W. Aloui, A. Mleiki, H. Rahmouni
Institution: University of Kairouan
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,160
OpenAlex ID: W4413136411