# Effect of LaNiO3 on the impedance and dielectric properties of CoFe2O4: a high temperature study

## TL;DR

This study investigates how adding LaNiO3 affects the impedance and dielectric properties of CoFe2O4 nanocomposites at high temperatures, revealing insights into relaxation processes and charge transport mechanisms.

## Contribution

It provides a detailed analysis of the impact of LaNiO3 content on impedance, dielectric behavior, and relaxation phenomena in CoFe2O4 composites at elevated temperatures.

## Key findings

- Reduced activation energy at grain boundaries with LNO addition
- Tunable interband transition frequency via LNO content
- Charge carriers exhibit short-range hopping across boundaries

## Abstract

We report the high temperature impedance and dielectric measurement of the nanocomposites comprising of CoFe2O4 (CFO) and LaNiO3 (LNO) by changing the content of LaNiO3 (0, 5, 10 and 15 %). The aim of the present study is to relate the structural defects expected at the interfaces of the composites with the result of impedance and dielectrics. The result separately shows the grain, grain boundary and electrode relaxation behaviour in the impedance and modulus spectroscopy. As calculated using Arrhenius law it indicates a reduced activation energy of the grain boundary in the presence of LNO compared to pure CFO. This assists the charge carriers for short range hopping across the boundary as reflected from ac conductivity. The dielectric constant at high frequency side manifests the interband transition in both pure CFO and the composite materials. The frequency of the transition can be tuned by LNO content. Thus this detail study will help to understand the relaxation phenomenon and dielectric behaviour in the presence of structural defects and disorder.