A novel strategy to achieve NaGdF₄:Eu³⁺ nanofibers with color‐tailorable luminescence and paramagnetic performance

Abstract

Luminescent‐magnetic bifunctional NaGdF4:Eu3+ nanofibers were fabricated through the bond of electrospinning followed by calcination with fluorination technology for the first time. The structure, morphologies, luminescence, and magnetism of nanofibers have been characterized using various techniques. X‐ray diffraction measurement indicates that NaGdF4:Eu3+ nanofibers are hexagonal phase. Scanning electron microscope measurement shows that the mean diameters of electrospinning‐made polyvinyl pyrrolidone/[NaNO3+Gd(NO3)3+Eu(NO3)3] composite nanofibers and NaGdF4:Eu3+ nanofibers are, respectively, 428±4 and 231±4 nm under the confidence level of 95%. Under 274‐nm ultraviolet light excitation, NaGdF4:Eu3+ nanofibers exhibit characteristic 5D3,2,1,0→7FJ emissions of Eu3+ and the tendency of color tones of samples varies from blue, cold white, warm white to red via varying Eu3+ content. In addition, samples exhibit paramagnetic features and the magnetic properties of NaGdF4:Eu3+ nanofibers are tailorable by modulating the doping concentration of Eu3+. More importantly, the color‐tailorable luminescence and paramagnetic properties are simultaneously realized in single‐phase NaGdF4:Eu3+ nanofibers, which ideally suit to apply in many fields such as lighting and color displays, bioimaging, and magnetic resonance imaging. This design conception and construction strategy may provide some new guidance for synthesizing other rare‐earth fluorides nanomaterials of multifarious morphologies.

New single‐component multicolor emission Na1−xAl1+2xSi1−2xO4:xBi3+/Eu3+ phosphors via energy transfer

“…As shown in Figure , the excitation and emission spectra of single doped Eu 3+ ions NAS samples were described in detail. From Figure A, the excitation spectrum (left part) monitored at 609 nm consisted of a broad excitation peaks (200‐275 nm) and several sharp peaks (275‐500 nm), which were attributable to the strong charge transition broad band (CTB) O 2− → Eu 3+ absorption and the strong f → f transition absorption of Eu 3+ ( 7 F 0 → 5 H 3 , 5 D 4 , 5 L 7 , 5 L 6 , 5 D 3 , and 5 D 2 ), respectively . Under the excitation of 392 nm, the emission spectrum appeared as several sharp peaks at about 591, 609, 652, and 703 nm, which were ascribed to the 5 D 0 → 7 F J ( J = 1, 2, 3, 4) transitions, respectively .…”

“…5 H 3 , 5 D 4 , 5 L 7 , 5 L 6 , 5 D 3 , and 5 D 2 ), respectively. 31 Under the excitation of 392 nm, the emission spectrum appeared as several sharp peaks at about 591, 609, 652, and 703 nm, which were ascribed to the 5 D 0 ? 7 F J (J = 1, 2, 3, 4) transitions, respectively.…”

Controllable synthesis of glass ceramics containing YF3:Eu3+ nanocrystals: Well‐preserved Eu and prolonged lifetime

“…Due to the low vibration phonon energy, fluorides nanocrystals (NCs) considered to be an ideal matrix of trivalent rare earth ions to promote the luminescent efficiency and prolong the lifetime . Among them, YF 3 NCs with low phonon energy (360 cm −1 ), wide bandgap and comparable ion size of Y with Eu + ion, has aroused considerable attention as host matrix of Eu 3+ .…”

Efficient red‐emitting phosphor of Eu3+‐activated (Na0.5Gd1.5)(TiSb)O7 derived via cation‐substitutions in Gd‐Pyrochlore

“…Second, microstructures of Eu 3+ ions can greatly influence the emission transitions of 5 D 0 – 7 F 2 (electric dipole) and 5 D 0 – 7 F 1 (magnetic dipole) . Eu 3+ ‐doped Gd 2 Ti 2 O 7 exhibits a typical yellow‐red luminescence color because of its cubic‐type host with the center of symmetry ( D 3d ) of Gd 3+ ions .…”

“…Second, microstructures of Eu 3+ ions can greatly influence the emission transitions of 5 D 0 -7 F 2 (electric dipole) and 5 D 0 -7 F 1 (magnetic dipole). 7,[17][18][19][20] Eu 3+ -doped Gd 2 Ti 2 O 7 exhibits a typical yellow-red luminescence color 6-12 because of its cubic-type host with the center of symmetry (D 3d ) of Gd 3+ ions. 21 Consequently, the cation substitution produces a tunable color of Eu 3+ by adjusting the symmetry in Gd 2 Ti 2 O 7 .…”