Amphotericity-spectroscopy correlations in Eu doped sodium bismuth titanate (Na0.5Bi0.5TiO3)

Santosh Behara, R. Hari Krishna, Muralidhar Miryala, Masato Murakami, Mohammad Irfan, S. Najma, Tiju Thomas

Research output: Contribution to journalArticle

Abstract

Optical characteristics of a doped material depend on the site wherein the dopant resides. In mixed A-site perovskites, the dopant has several possibilities. This, in turn, correlates with the emission spectrum of the doped material. Here we choose Eu3+ as the dopant since it is a well-known and efficient red-luminophore. Sodium bismuth titanate (NBT-Na0.5Bi0.5TiO3) is selected as a host due to its ability to accommodate Eu over large concentration windows while maintaining optical activity. For compositions x ≥ 0.04, we show that Eux:NBT has amphoteric behavior (i.e., simultaneous dopant substitution in two competing sites). Eu3+ occupancy in Bi and Ti-sites are quantitatively estimated using Rietveld refinement. Also, the appearance of A1g breathing vibrational mode (830–860 cm−1) in Raman spectra shows the presence of Eu3+ on the Ti-site. Photoluminescence (PL) emission shows sharp and intense bands at ∼592 nm, ∼615 nm, and ∼687 nm, and one weak band at ∼652 nm, corresponding to f–f transitions of Eu3+. To evaluate the optical characteristics with varying site-substitution of Eu3+; Judd–Ofelt parameters and radiative properties are calculated for the first time in this mixed A-site titanate system. From the values of asymmetric ratios; Eu3+ ion is shown to occupy the non-centrosymmetrical sites (Bi-sites) of NBT. However, at x = 0.04, Ω2 < Ω4, which indicates long-range effects and hence Eu occupancy in centrosymmetric sites (Ti-sites). This study opens up avenues for further exploration of correlations between dopant-concentration, amphotericity, and spectrochemical response in other systems. The amphoteric behavior of dopants can tune emission intensities and produce multi-emission colors using a single-dopant. This would have implications for luminescence-based applications.

Original languageEnglish
Article number100426
JournalMaterialia
Volume7
DOIs
Publication statusPublished - 2019 Sep 1

Fingerprint

Bismuth
Sodium
Doping (additives)
Spectroscopy
Substitution reactions
Rietveld refinement
bismuth titanate
Raman scattering
Luminescence
Photoluminescence
Ions
Color
Chemical analysis

Keywords

  • Amphoteric behavior
  • Eu-doping
  • Judd–Ofelt parameters
  • Raman spectra
  • Rare-earth doping
  • Sodium bismuth titanate

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Amphotericity-spectroscopy correlations in Eu doped sodium bismuth titanate (Na0.5Bi0.5TiO3). / Behara, Santosh; Hari Krishna, R.; Miryala, Muralidhar; Murakami, Masato; Irfan, Mohammad; Najma, S.; Thomas, Tiju.

In: Materialia, Vol. 7, 100426, 01.09.2019.

Research output: Contribution to journalArticle

Behara, Santosh ; Hari Krishna, R. ; Miryala, Muralidhar ; Murakami, Masato ; Irfan, Mohammad ; Najma, S. ; Thomas, Tiju. / Amphotericity-spectroscopy correlations in Eu doped sodium bismuth titanate (Na0.5Bi0.5TiO3). In: Materialia. 2019 ; Vol. 7.
@article{45b0e128ddc644bf819d187f91fb4407,
title = "Amphotericity-spectroscopy correlations in Eu doped sodium bismuth titanate (Na0.5Bi0.5TiO3)",
abstract = "Optical characteristics of a doped material depend on the site wherein the dopant resides. In mixed A-site perovskites, the dopant has several possibilities. This, in turn, correlates with the emission spectrum of the doped material. Here we choose Eu3+ as the dopant since it is a well-known and efficient red-luminophore. Sodium bismuth titanate (NBT-Na0.5Bi0.5TiO3) is selected as a host due to its ability to accommodate Eu over large concentration windows while maintaining optical activity. For compositions x ≥ 0.04, we show that Eux:NBT has amphoteric behavior (i.e., simultaneous dopant substitution in two competing sites). Eu3+ occupancy in Bi and Ti-sites are quantitatively estimated using Rietveld refinement. Also, the appearance of A1g breathing vibrational mode (830–860 cm−1) in Raman spectra shows the presence of Eu3+ on the Ti-site. Photoluminescence (PL) emission shows sharp and intense bands at ∼592 nm, ∼615 nm, and ∼687 nm, and one weak band at ∼652 nm, corresponding to f–f transitions of Eu3+. To evaluate the optical characteristics with varying site-substitution of Eu3+; Judd–Ofelt parameters and radiative properties are calculated for the first time in this mixed A-site titanate system. From the values of asymmetric ratios; Eu3+ ion is shown to occupy the non-centrosymmetrical sites (Bi-sites) of NBT. However, at x = 0.04, Ω2 < Ω4, which indicates long-range effects and hence Eu occupancy in centrosymmetric sites (Ti-sites). This study opens up avenues for further exploration of correlations between dopant-concentration, amphotericity, and spectrochemical response in other systems. The amphoteric behavior of dopants can tune emission intensities and produce multi-emission colors using a single-dopant. This would have implications for luminescence-based applications.",
keywords = "Amphoteric behavior, Eu-doping, Judd–Ofelt parameters, Raman spectra, Rare-earth doping, Sodium bismuth titanate",
author = "Santosh Behara and {Hari Krishna}, R. and Muralidhar Miryala and Masato Murakami and Mohammad Irfan and S. Najma and Tiju Thomas",
year = "2019",
month = "9",
day = "1",
doi = "10.1016/j.mtla.2019.100426",
language = "English",
volume = "7",
journal = "Materialia",
issn = "2589-1529",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Amphotericity-spectroscopy correlations in Eu doped sodium bismuth titanate (Na0.5Bi0.5TiO3)

AU - Behara, Santosh

AU - Hari Krishna, R.

AU - Miryala, Muralidhar

AU - Murakami, Masato

AU - Irfan, Mohammad

AU - Najma, S.

AU - Thomas, Tiju

PY - 2019/9/1

Y1 - 2019/9/1

N2 - Optical characteristics of a doped material depend on the site wherein the dopant resides. In mixed A-site perovskites, the dopant has several possibilities. This, in turn, correlates with the emission spectrum of the doped material. Here we choose Eu3+ as the dopant since it is a well-known and efficient red-luminophore. Sodium bismuth titanate (NBT-Na0.5Bi0.5TiO3) is selected as a host due to its ability to accommodate Eu over large concentration windows while maintaining optical activity. For compositions x ≥ 0.04, we show that Eux:NBT has amphoteric behavior (i.e., simultaneous dopant substitution in two competing sites). Eu3+ occupancy in Bi and Ti-sites are quantitatively estimated using Rietveld refinement. Also, the appearance of A1g breathing vibrational mode (830–860 cm−1) in Raman spectra shows the presence of Eu3+ on the Ti-site. Photoluminescence (PL) emission shows sharp and intense bands at ∼592 nm, ∼615 nm, and ∼687 nm, and one weak band at ∼652 nm, corresponding to f–f transitions of Eu3+. To evaluate the optical characteristics with varying site-substitution of Eu3+; Judd–Ofelt parameters and radiative properties are calculated for the first time in this mixed A-site titanate system. From the values of asymmetric ratios; Eu3+ ion is shown to occupy the non-centrosymmetrical sites (Bi-sites) of NBT. However, at x = 0.04, Ω2 < Ω4, which indicates long-range effects and hence Eu occupancy in centrosymmetric sites (Ti-sites). This study opens up avenues for further exploration of correlations between dopant-concentration, amphotericity, and spectrochemical response in other systems. The amphoteric behavior of dopants can tune emission intensities and produce multi-emission colors using a single-dopant. This would have implications for luminescence-based applications.

AB - Optical characteristics of a doped material depend on the site wherein the dopant resides. In mixed A-site perovskites, the dopant has several possibilities. This, in turn, correlates with the emission spectrum of the doped material. Here we choose Eu3+ as the dopant since it is a well-known and efficient red-luminophore. Sodium bismuth titanate (NBT-Na0.5Bi0.5TiO3) is selected as a host due to its ability to accommodate Eu over large concentration windows while maintaining optical activity. For compositions x ≥ 0.04, we show that Eux:NBT has amphoteric behavior (i.e., simultaneous dopant substitution in two competing sites). Eu3+ occupancy in Bi and Ti-sites are quantitatively estimated using Rietveld refinement. Also, the appearance of A1g breathing vibrational mode (830–860 cm−1) in Raman spectra shows the presence of Eu3+ on the Ti-site. Photoluminescence (PL) emission shows sharp and intense bands at ∼592 nm, ∼615 nm, and ∼687 nm, and one weak band at ∼652 nm, corresponding to f–f transitions of Eu3+. To evaluate the optical characteristics with varying site-substitution of Eu3+; Judd–Ofelt parameters and radiative properties are calculated for the first time in this mixed A-site titanate system. From the values of asymmetric ratios; Eu3+ ion is shown to occupy the non-centrosymmetrical sites (Bi-sites) of NBT. However, at x = 0.04, Ω2 < Ω4, which indicates long-range effects and hence Eu occupancy in centrosymmetric sites (Ti-sites). This study opens up avenues for further exploration of correlations between dopant-concentration, amphotericity, and spectrochemical response in other systems. The amphoteric behavior of dopants can tune emission intensities and produce multi-emission colors using a single-dopant. This would have implications for luminescence-based applications.

KW - Amphoteric behavior

KW - Eu-doping

KW - Judd–Ofelt parameters

KW - Raman spectra

KW - Rare-earth doping

KW - Sodium bismuth titanate

UR - http://www.scopus.com/inward/record.url?scp=85070508868&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070508868&partnerID=8YFLogxK

U2 - 10.1016/j.mtla.2019.100426

DO - 10.1016/j.mtla.2019.100426

M3 - Article

AN - SCOPUS:85070508868

VL - 7

JO - Materialia

JF - Materialia

SN - 2589-1529

M1 - 100426

ER -