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A series of Gd3+-doped BaMgAl10O17 phosphors have been successfully synthesized using a low-temperature solution combustion method. The crystal structure and phase purity of the samples were characterized using x-ray powder diffraction analysis. The optimal concentration of Gd3+ dopant in BaMgAl10O17 was determined through measurements of the photoluminescence spectra of the phosphors. All phosphors showed narrowband UVB emission at 313 nm with excitation wavelength at 272 nm. Relatively dominant electron spin resonance (ESR) lines were observed with geff ≈ 1.98. 2.7, 4.2, and 5.95 in phosphors with low concentration of dopant Gd3+ ion. At higher dopant concentrations, the spectrum appeared to be U-like with prominent lines at geff ≈ 1.99, 2.7, 4.2, and 5.94. Distortions in the neighborhood of Gd3+ ion led to ESR lines in the low-field region of the spectrum. [ABSTRACT FROM AUTHOR]

Abstract Gd3+-doped Ca 3 Al 2 O 6 (CA3) phosphor was synthesized using a combustion method. The crystal structure and the phase purity of the sample were characterized by X-ray powder diffraction (XRD). The surface morphology of the sample was studied using a scanning electronic microscope (SEM). The Gd3+-doped Ca 3 Al 2 O 6 phosphor showed an absorption band in the UV spectral region and a narrowband-UVB emission under the excitation of 273 nm. The narrowband-UVB emission at 314 nm corresponds to the 6P 7/2 → 8S 7/2 transition of the Gd3+. A dominant line in the region around g = 2.0 was observed in the electron spin resonance (ESR) spectrum of the prepared phosphor. [ABSTRACT FROM AUTHOR]

Abstract Undoped Y 2 O 3 and Gd3+-doped Y 2 O 3 samples were synthesized using a sol-gel method. The samples were characterized by X-ray powder diffraction (XRD), a scanning electron microscope (SEM), photoluminescence (PL), and electron paramagnetic resonance (EPR). The room-temperature PL spectrum was recorded to study the bands that are due to the Gd3+. The photoluminescence analyses of the sample confirm the presence of the Gd3+ ions in the Y 2 O 3 matrix. EPR spectra of the samples confirmed the presence of Gd3+ ions in Y3+ sites with cubic symmetry. [ABSTRACT FROM AUTHOR]