Reddish-orange-emitting and paramagnetic properties of GdVO₄:Sm³⁺/Eu³⁺ multifunctional nanomaterials

Abstract

A series of GdVO4: Sm 3+ , Eu 3+ reddish-orange-emitting nanophosphors were successfully prepared by a simple one-step hydrothermal method. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectrometer (EDS), transmission electron microscope (TEM), photoluminescence (PL) spectra, fluorescence lifetime, PL quantum-efficiency (QE) and vibrating sample magnetometer (VSM) were utilized to characterize the as-prepared samples. The results 10show that the individual Sm 3+ or Eu 3+ ions activated GdVO4 phosphors exhibit excellent emission properties in their respective regions and the bright blue light from VO4 3group can be observed under the excitation of ultraviolet (313 nm). The emission intensity of Sm 3+ singly activated GdVO4 phosphors reaches the maximum when the content of Sm 3+ is 0.025, of which the critical distance (RSm-Sm) is calculated to be 18.42 Å. Strong reddish-orange emissions can be seen in Sm 3+ and Eu 3+ ions co-doped 15 GdVO4 phosphors under ultraviolet light irradiation. In addition, the energy transfer phenomenon from Sm 3+ to Eu 3+ ions is clearly observed in GdVO4: Sm 3+ , Eu 3+ , which is confirmed to be an electric quadrupole-quadrupole interaction and the energy transfer efficiency can reach a maximum at 92.5%. More significantly, the color becomes more saturated with the increasing of Eu 3+ or Sm 3+ ions content. Moreover, the as-prepared samples exhibit paramagnetic properties at room temperature. This type of 20 multifunctional reddish-orange-emitting nanophosphor has promising applications in the fields of UV/n-UV WLEDs and biomedical science. 65 transfer from Sm 3+ ions to Eu 3+ ions. Moreover, Ln 3+ ions doped GdVO4 nanocrystals can function as multifunctional materials for their promising applications in biomedical field ascribed to the high magnetic moment and isotropic electronic ground state 8 S7/2 of Gd 3+ ions. So it is highly valuable to prepare GdVO4: Sm 3+ , 65 the latter is O 2--V 5+ CT, which corresponds to the transitions from the 1 A2( 1 T1) ground state and to 1 A1( 1 E) and 1 E( 1 T2) excited state of VO4 3group in the view of molecular orbital theory 35 . Furthermore, there are some weak absorption peaks resulting from f-f transitions within the 4f 6 configuration of the Eu 3+ ions 70 from the 7 F0 ground state to the 5 D4 (363 nm), 5 G3 (377 nm), 5 L7 (384 nm), 5 L6 (396 nm), 5 D3 (418 nm), 5 D2 (467 nm) excited states can be discovered. It can be clearly found that the f-f transitions of Eu 3+ from 350 nm to 470 nm match well with the n-

Orange-Reddish Light Emitting Phosphor GdVO4:Sm3+ Prepared by Solution Combustion Synthesis

“…In our measurements, all luminescence bellow 500 nm is cut o by the optical lter used for blocking the OPO excitation. e spectral shape of host luminescence, detected by us only above 500 nm, is similar to spectra presented in [1,9,28]. e GdVO 4 luminescence is ascribed to the VO 4 3− group.…”

“…86-0996). Ionic radius of the Sm 3+ ion (0.964Å) is a slightly larger than that of Gd 3+ ion (0.938Å), which indicates that Sm 3+ could be successfully incorporated into the GdVO 4 host lattice by substituting Gd 3+ without changing the tetragonal zircon type structure of GdVO 4 [9].…”

“…Gadolinium vanadate (GdVO 4 ) is a very important host for the luminescence of rare earth activators which find applications in the high-power solid state lasers, X-ray medical radiography, energy-saving fluorescent lamps, artificial production of light, other display devices [5][6][7][8][9][10][11], and temperature sensing [4]. Phosphors based on gadolinium compounds play an important role because the Gd 3+ ion (4f 7 ) has its lowest excited level at relatively high energy, which is due to the stability of the half-filled shell ground state [6].…”

Bimodal Nd-Doped LuVO4 Nanoprobes Functionalized with Polyacrilic Acid for X-Ray Computed Tomography and NIR Luminescent Imaging

“…Several compounds have been assayed for such a purpose, among which rare earth vanadate (REVO 4 )-based nanophosphors composed by a REVO 4 matrix in which different luminescent lanthanide (Ln) cations are introduced as dopants, have been recently the focus of much attention. In particular, Ln-doped REVO 4 (RE = Y, La, Gd; Ln = Eu, Tb, Dy, Sm, Nd, Yb), have been proposed as excellent probes for luminescent "in vitro" bioimaging and biosensing [2][3][4][5][6][7][8][9][10], owing to their intense luminescence on excitation by UV light through an energy transfer process from the vanadate matrix to the Ln 3+ cations [11]. However, the need for UV excitation is a drawback for in vivo bioapplications because of the potential damage that such radiation may cause to living organisms.…”

Single-phase and warm white-light-emitting phosphors CaLa2−−(MoO4)4: xDy3+, yEu3+: Synthesis, luminescence and energy transfer

“…8 and 9. In order to understand the energy transfer mechanism from Dy 3 þ to Eu 3 þ ions, the Dexter's energy transfer formula of multipolar interaction can be described as [24]:…”