Saved in:
Bibliographic Details
Main Authors: Sarkar, Sourav, Mandal, Kalyan
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.24124
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908995165356032
author Sarkar, Sourav
Mandal, Kalyan
author_facet Sarkar, Sourav
Mandal, Kalyan
contents Negative permittivity metamaterial is a scientifically rich avenue due to its tremendous application in several arena of materials research including novel superlens, band-gap materials, invisibility cloaks, antenna and filter design. Traditionally, epsilon negative (ENG) behaviour is achieved in multi-phase composites with the addition of conducting metal fillers. However, this study reports colossal ENG feature in a single phase Calcium Ferrite for a particular nano hollow spherical (NHS) morphology, without the use of any filler. On the contrary, the same material synthesized in a different morphology, namely, nano solid sphere (NSS) shows conventional dielectric behaviour. Occurrence of ENG is successfully interpreted with the phase inversion of dominant polarization within the hollow cavity of NHS. This report marks a significant step in realizing colossal ENG in a single phase material just by restructuring the nanoscale morphology.
format Preprint
id arxiv_https___arxiv_org_abs_2604_24124
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Geometry selective colossal negative dielectric permittivity in CaFe2O4 nanostructures
Sarkar, Sourav
Mandal, Kalyan
Mesoscale and Nanoscale Physics
Materials Science
Other Condensed Matter
Negative permittivity metamaterial is a scientifically rich avenue due to its tremendous application in several arena of materials research including novel superlens, band-gap materials, invisibility cloaks, antenna and filter design. Traditionally, epsilon negative (ENG) behaviour is achieved in multi-phase composites with the addition of conducting metal fillers. However, this study reports colossal ENG feature in a single phase Calcium Ferrite for a particular nano hollow spherical (NHS) morphology, without the use of any filler. On the contrary, the same material synthesized in a different morphology, namely, nano solid sphere (NSS) shows conventional dielectric behaviour. Occurrence of ENG is successfully interpreted with the phase inversion of dominant polarization within the hollow cavity of NHS. This report marks a significant step in realizing colossal ENG in a single phase material just by restructuring the nanoscale morphology.
title Geometry selective colossal negative dielectric permittivity in CaFe2O4 nanostructures
topic Mesoscale and Nanoscale Physics
Materials Science
Other Condensed Matter
url https://arxiv.org/abs/2604.24124