Abstract
Trivalent rare-earth (RE3+ = Eu3+, Tb3+, Dy3+, and Sm3+) ions activated Gd2O(CO 3)2·H2O chrysanthemum-like flowers are prepared by a modified urea-based homogeneous precipitation via a template free hydrothermal synthesis route. Subsequently, Gd2O3 monodispersed spheres were obtained after calcining at 750 °C. The growth mechanism of the Gd2O(CO3)2·H 2O:RE3+ chrysanthemum-like morphology (homogeneous precipitation) and their transformation to monodispersed spheres (heterogeneous nucleation) are established by taking scanning electron microscope and transmission electron microscope images of the intermediate products. The thermogravimetric analysis, Fourier transform infrared analyses confirmed the decomposition of CO2 and OH groups, and the corresponding XRD patterns exhibited the Gd2O(CO3)2·H 2O and cubic Gd2O3 phases. The photoluminescence measurements are used to explore the emission behavior of different RE3+ ions activated Gd2O3 spheres. The Gd2O3:Eu3+ shows gorgeous red emission with high purity red color as compared to the commercial Y2O 3:Eu3+ phosphors. Gd2O3:Tb 3+, Gd2O3:Dy3+ and Gd 2O3:Sm3+ exhibit green, yellow and rich orange emissions, respectively. The Tb3+/Eu3+ co-doped sample shows warm white light by controlling the energy transfer. At minimal parameters, the cathodoluminescence intensity of Gd2O 3:Eu3+ is beyond the experimental limit for 5 kV of accelerating voltage. The CIE chromaticity coordinates were also calculated from the PL and CL spectra of RE3+ ions to establish their color richness.
Original language | English |
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Pages (from-to) | 11400-11410 |
Number of pages | 11 |
Journal | Dalton Transactions |
Volume | 42 |
Issue number | 32 |
DOIs | |
State | Published - 28 Sep 2013 |