Effects of Li addition on the luminescent properties of LiSrPO4:Eu3+ excited with X-ray and ultraviolet radiation

• Published in: Journal of alloys and compounds Vol. 836; p. 155388
• Main Authors: Nascimento, Patresio A.M., Silva, Ariovaldo J.S., Carvalho, Iure S., Silva, Ronaldo S., Paschoal, Carlos William A., Moulton, Benjamin J.A., Sampaio, David V., Freire, R.S., Rezende, Marcos V.dos S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25-09-2020; Elsevier BV
• Subjects: Europium; Ionizing radiation; LiSrPO4; Lithium; Lithium variation; Luminescence; Morphology; Optical properties; Phosphors; Photoluminescence; Sol-gel processes; Stoichiometry; Symmetry; Ultraviolet radiation; X ray absorption; X-ray absorption spectroscopy; X-ray diffraction; X-ray excited optical luminescence; Lithium variation; X-ray absorption spectroscopy; LiSrPO4; X-ray excited optical luminescence; Luminescence
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.155388

Li1+xSr0.99PO4:Eu0.01 (x = 0.1, 0.3 or 0.5) phosphors are prepared using glucose with a modified sol-gel method. X-ray diffraction (XRD), scanning electron microscopy and photoluminescence and X-ray absorption spectroscopy are used to characterize the structural and optical behaviour of the phosphors. LSPOE powders have been successfully synthesized by sol-gel route and confirmed by XRD. A variation in lithium stoichiometry does not contribute to significant changes in structural properties, as probed by XRD. The samples have a partially spherical morphology with a high degree of particle agglomeration. The emission intensity of Eu3+ varies with the increase in Li+ content, in agreement with the variation of the symmetric factor. This behaviour verifies that the Eu3+ ion is in a site of low symmetry. The X-ray absorption near edge structure results reveal that the reduction of Eu3+ to Eu2+ is induced by ionising radiation and the intensity of the X-ray excited optical luminescence emission is inversely proportional to the concentration of lithium.
•Eu3+-doped LiSrPO4 (LSPO) was produced by a modified sol-gel route.•Structural and morphology characterization was performed by XRD and SEM.•X-ray Absorption Spectroscopy (XAS) were used to characterize valence of dopant.•Photoluminescent (PL) were used to characterize the optical behavior.•Reduction of Eu3+ to Eu2+ is induced by ionizing radiation.