Ferroelectric order driven Eu3+ photoluminescence in BaZrxTi1\u2212xO3 perovskite

Giovanna Canu,Gregorio Bottaro,Lavinia Curecheriu,Chiara Costa,Lidia Armelao,Vincenzo Buscaglia,Liliana Mitoseriu,Oana Condurache,Maria Teresa Buscaglia

doi:10.1038/s41598-019-42897-1

Abstract

The ability to tune and enhance the properties of luminescent materials is essential for enlarging their application potential. Recently, the modulation of the photoluminescence emission of lanthanide-doped ferroelectric perovskites by applying an electric field has been reported. Herein, we show that the ferroelectric order and, more generally the polar order, has a direct effect on the photoluminescence of Eu3+ in the model BaZrxTi1−xO3 perovskite even in the absence of an external field. The dipole arrangement evolves with increasing x from long-range ferroelectric order to short-range order typical of relaxors until the non-polar paraelectric BaZrO3 is achieved. The cooperative polar interactions existing in the lattice (x < 1) promote the off-center displacement of the Eu3+ ion determining a change of the lanthanide site symmetry and, consequently, an abrupt variation of the photoluminescence emission with temperature. Each type of polar order is characterized by a distinct photoluminescence behaviour.

Highlights

The ability to tune and enhance the properties of photoluminescent materials by changing the emission wavelengths, intensity, band-shape, emission quantum yields and excited states lifetime is essential for optimizing the performance of devices and understanding the luminescence mechanisms
Long-range order typical of conventional ferroelectrics prevails for 0.0 ≤ x ≤ 0.15, whereas the correlation length of polar order is reduced for 0.15 < x ≤ 0.25 corresponding to a diffuse ferroelectric to paraelectric transition
For ceramic BZ5 (Fig. 1b), TC decreases to 108 °C and the temperature of the O/T transition increases to 50 °C

Summary

Introduction

The ability to tune and enhance the properties of photoluminescent materials (phosphors) by changing the emission wavelengths, intensity, band-shape, emission quantum yields and excited states lifetime is essential for optimizing the performance of devices and understanding the luminescence mechanisms. Www.nature.com/scientificreports the heterogeneous local structure of the relaxor ceramics, corresponding to Ti-rich PNRs embedded in a cubic paraelectric matrix26,27, further increases the disorder of the europium sites.

Results

Conclusion