3 февруари 2022
Brunckova, H., Rocha, L.A., Nassar, E.J., Moscardini, S.B., Kolev, H..
(
Христо Колев;
)
Abstract
Thin films of lanthanide orthoniobate LnNbO4 (LnNO) and orthotantalate LnTaO4 (LnTO), (Ln?=?Nd, Sm, Eu) were fabricated using the sol–gel method with subsequent spin-coating on the PbZrO3/Al2O3 substrate and annealing at 1000°C. X-ray diffraction patterns showed monoclinic M-LnNbO4 or M?-LnTaO4, which coexists with the orthorhombic or tetragonal phase. X-ray photoelectron spectroscopy demonstrated the presence of Nd3+, Sm3+/Sm2+ and Eu3+/Eu2+ ions. The luminescence properties of polymorphic films were investigated. Excitation spectra of PbZrO3 interlayer represented broad bands at 410 and 550?nm that were assigned to charge transfer bands (CTB). In all films, the CTB broad band at ~275?nm related to charge transfer transition of Ln3+?O2? and NbO43? or TaO43? groups. In excitation spectra, 4I9/2?4G5/2 (Nd3+), 6H5/2?6P3/2 (Sm3+) and 7F0?5L6 (Eu3+) transitions (at 585, 402 and 395?nm), respectively were found to be more intense than any other Ln3+ transition. The emission spectra showed narrow and intense bands at 1065, 600, and 614?nm that were ascribed to Nd3+, Sm3+, and Eu3+ 4f–f intraconfigurational transitions 4F3/2?4I11/2, 4G5/2?6H7/2, and 5D0?7F2, respectively. The excellent luminescence properties of films make them new potential groups for visible and/or near-infrared applications such as sensors and imaging equipment.
Luminescence, 37, 4, John Wiley & Sons Ltd, 2022, ISSN:1522-7243, DOI:10.1002/bio.4205, 642-655. SJR (Scopus):0.391, JCR-IF (Web of Science):2.464 Q2 (Web of Science)
https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/epdf/10.1002/bio.4205
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