Journal of the American Ceramic Society, Vol.100, No.12, 5620-5628, 2017
Enhanced electrical properties and strong red light-emitting in Eu3+-doped Sr1.90Ca0.15Na0.9Nb5O15 ceramics
The luminescent-ferroelectic materials based on Sr1.90Ca0.15Na0.9Nb5O15 (SCNN) matrix doping with Eu3+ were synthesized by the conventional solid-state reaction method. The crystal structure, photoluminescence, thermal stability, dielectric, ferroelectric, and piezoelectric behaviors were systematically investigated. XRD results revealed that Eu3+ introduction could induce the tungsten bronze phase transition from orthorhombic to tetragonal structures. The dielectric spectra of all specimens showed two broad dielectric anomalies: a high-temperature ferroelectric phase transition (T-c) and a low-temperature ferroelastic phase transition (T-s), both of which were suppressed at higher Eu3+ concentrations. The enhanced electrical properties were obtained in a proper Eu3+ concentration range of 0.03-0.05. For all SCNN:xEu(3+) samples, the strong red emission peak at 617 nm originating from the electric dipole transition of D-5(0) -> F-7(2) was excited by different light excitations of 395 or 463 nm. Our results demonstrated that Eu3+-doped SCNN materials might have promising potential in advanced multifunctional optoelectronic applications.
Keywords:dielectric materials/properties;ferroelectricity/ferroelectric materials;luminescence;piezoelectric materials/properties;tungsten/tungsten compounds