Effects of lanthanide amphoteric incorporation on structural, electrical, and photoluminescence properties of BaTi0.925(Yb0.5Nb0.5)(0.075)O-3 ceramic
Résumé
The influence of the lanthanide incorporation in lead-free ferroelectric BaTi0.925(Yb0.5Nb0.5)(0.075)O-3 (BTYN) perovskite on its structural, dielectric, ferroelectric behavior, piezoelectric and photoluminescence properties was investigated. X-ray diffraction study permitted the identification of an isostructural phase with P4mm-tetragonal symmetry. Praseodymium was found to occupy only Ba-sites instead of the distribution over both sites as in the case of Nd and Eu elements. The improvement of dielectric and ferroelectric properties obtained from Nd- and Eu-phase is discussed in terms of amphoteric behavior effect of these elements. Incorporation of Ln(3+) was found to improve piezoelectric properties from 3 pC/N for BTYN to 18, 40 and 26 pC/N for BTYN:Eu, BTYN:Nd and BTYN:Pr respectively. The photoluminescence (PL) properties of Pr-phase gives rise to the expected electronic transitions associate to Pr3+ ions. In contrast, PL carried out on Eu- and Nd-phases showed dominate strong red emission centered at 690 nm attributed to defect structure and non-stoichiometry. The simultaneous existence of ferroelectric piezoelectric and luminescence properties in the titled system could be promising for electro-optical applications. (C) 2017 Elsevier B.V. All rights reserved.