Influence of electric field on the Eu+3 photolumiscence in lead-free ferroelectric Na1/2Bi1/2TiO3

TL;DR

This study explores how electric fields influence Eu+3 photoluminescence and structural order in lead-free Na1/2Bi1/2TiO3, revealing potential for using luminescence as a probe for structural changes in ferroelectric materials.

Contribution

It demonstrates the electric-field-induced suppression of nano-scale structural disorder and the transition to a long-range ferroelectric state in Eu-modified Na1/2Bi1/2TiO3.

Findings

Electric field irreversibly suppresses structural heterogeneity.

Eu+3 luminescence correlates with structural ordering.

Structural disorder opens radiative transition channels.

Abstract

Eu modified Na1/2Bi1/2TiO3 (NBT) was investigated for electric-field induced Eu+3 photoluminescence (PL) and structural changes. Detailed analysis revealed that below a critical Eu composition electric field irreversibly suppresses the structural heterogeneity inherent of the host matrix NBT and brings about a long range ferroelectric state with rhombohedral (R3c) distortion. PL study revealed that structural disorder on the nano-scale opens new channels of radiative transitions which can be suppressed by electric field. This study suggests that Eu+3 luminescence can be used to probe the relative degree of field induced structural ordering in relaxor ferroelectrics and also in high performance piezoelectric alloys where electric field couples very strongly with the lattice and structural degrees of freedom.