Structural, Electrical, Magnetic and Impedance Behaviour of NdFeO3 Modified Ba0.7Sr0.3TiO3 Ceramics

TL;DR

This study investigates the structural, electrical, magnetic, and impedance properties of NdFeO3 modified Ba0.7Sr0.3TiO3 ceramics, revealing phase coexistence, microstructure details, and conduction mechanisms influenced by oxygen vacancies.

Contribution

It provides new insights into the phase composition, microstructure, and electrical conduction mechanisms of NdFeO3-modified Ba0.7Sr0.3TiO3 ceramics using comprehensive characterization techniques.

Findings

Coexistence of tetragonal and hexagonal phases confirmed.

Impedance spectroscopy reveals grain and grain boundary contributions.

Oxygen vacancies influence relaxation and conduction processes.

Abstract

NdFeO3 modified polycrystalline ceramics with composition (NdFeO3)0.1-(Ba0.7Sr0.3TiO3)0.9 (NFBST) ceramics have been synthesized via solid-state reaction route. The Rietveld refinement of the XRD data confirmed the existence of a tetragonal phase (P4mm) and a hexagonal phase (P63/mmc) in the prepared sample. The coexistence of phases has been also further confirmed from the Raman spectroscopy. The SEM image revealed dense microstructure with well packed grains of different sizes. At room temperature lossy P-E loop and weak ferromagnetism is observed in NFBST system. Complex impedance spectroscopy (CIS) as a function of frequency (100 Hz to 1 MHz) at different temperatures (RT to 700K) has been employed to study the electrical behaviour in NFBST ceramic. Two semicircular arcs in the Cole-Cole plot manifested the grain and grain boundary contribution in overall impedance. The detail complex modulus analysis and ac fitted conductivity data authenticated correlated barrier hopping CBH to be responsible for electrical as well as conduction phenomena in NFBST. Oxygen vacancies are responsible for relaxation and conduction processes in NFBST ceramics as divulged from the activation energy values estimated from electrical impedance, modulus, and conductivity data.