Observation of plastoferrite character and semiconductor to metal transition in soft ferromagnetic Li0.5Mn0.5Fe2O4ferrite

TL;DR

This study reports the synthesis and characterization of Li0.5Mn0.5Fe2O4 ferrite, revealing a temperature-induced transition from semiconductor to metallic behavior and plastoferrite surface features at high sintering temperatures.

Contribution

It demonstrates the occurrence of a semiconductor to metal transition in Li0.5Mn0.5Fe2O4 ferrite related to sintering temperature and surface morphology changes, providing new insights into its electrical properties.

Findings

Surface morphology shows plastoferrite character above 1000°C.

Charge delocalization induces semiconductor to metal transition.

Metallic state confirmed by dielectric constant behavior.

Abstract

We prepared Li0.5Mn0.5Fe2O4 ferrite through chemical reaction in highly acidic solution and subsequent sintering of chemical routed powder at temperatures > 800 0C. Surface morphology showed plastoferrite character for sintering temperature > 1000 0C. Mechanical softening of metal-oxygen bonds at higher measurement temperatures stimulated delocalization of charge carriers, which were strongly localized in A and B sites of the spinel structure at lower temperatures. The charge delocalization process has activated semiconductor to metallic transition in ac conductivity curves, obeyed by Jonscher power law and Drude equation, respectively. Metallic state is also confirmed by the frequency dependence of dielectric constant curves.