Thermo and photoluminescence properties of Eu3+ activated hexagonal, monoclinic and cubic gadolinium oxide nanorods

Dhananjaya, N.; Nagabhushana, H.; Nagabhushana, B.M.; Rudraswamy, B.; Shivakumara, C.; Ramesh, K.; Chakradhar, R.P.S.

doi:10.1016/j.physb.2010.10.013

Cited by 26 publications

(14 citation statements)

References 41 publications

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“…The TL glow peak was deconvoluted using the Origin 8.0 software [31]. The estimated kinetic parameters for Gd 2 O 3 :Eu 3+ and Bi 3+ (5 mol%) co-doped Gd 2 O 3 :Eu 3+ (4 mol%) nanophosphors are tabulated in Table 1.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, characterization, thermo- and photoluminescence properties of Bi3+ co-doped Gd2O3:Eu3+ nanophosphors

Dhananjaya

Nagabhushana

et al. 2012

Appl. Phys. B

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Gd 2 O 3 :Eu 3+ (4 mol%) co-doped with Bi 3+ (Bi = 0, 1, 3, 5, 7, 9 and 11 mol%) ions were synthesized by a low-temperature solution combustion method. The powders were calcined at 800°C and were characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), Fourier transform infrared and UV-Vis spectroscopy. The PXRD profiles confirm that the calcined products were in monoclinic with little cubic phases. The particle sizes were estimated using Scherrer's method and Williamson-Hall plots and are found to be in the ranges 40-60 nm and 30-80 nm, respectively. The results are in good agreement with TEM results. The photoluminescence spectra of the synthesized phosphors excited with 230 nm show emission peaks at ∼590, 612 and 625 nm, which are due to the transitions 5 D 0 → 7 F 0 , 5 D 0 → 7 F 2 and 5 D 0 → 7 F 3 of Eu 3+ , respectively. It is observed that a significant quenching of Eu 3+ emission was observed under 230 nm excitation when Bi 3+ was co-doped. On the other hand, upon 350 nm excitation, the luminescent intensity of Eu 3+ ions was enhanced by incorporation of Bi 3+ (5 mol%) ions. The introduction of Bi 3+ ions broadened the excitation band of Eu 3+ of which a new strong band occurred ranging from 320 to 380 nm. This has been attributed to the 6s 2 → 6s6p transition of Bi 3+ ions, implying a very efficient energy transfer from Bi 3+ ions to Eu 3+ ions. The gamma radiation response of Gd 2 O 3 :Eu 3+ exhibited a dosimetrically useful glow peak at 380°C. Using thermoluminescence glow peaks, the trap parameters have been evaluated and discussed. The observed emission characteristics and energy transfer indicate that Gd 2 O 3 :Eu 3+ , Bi 3+ phosphors have promising applications in solid-state lighting.

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Section: Resultsmentioning

confidence: 99%

Synthesis, characterization, thermo- and photoluminescence properties of Bi3+ co-doped Gd2O3:Eu3+ nanophosphors

Dhananjaya

Nagabhushana

et al. 2012

Appl. Phys. B

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“…The peaks at 468 cm −1 were the characteristic stretching vibrations of Si O Si bridges. A weak absorption peak at 2397 cm −1 indicating the presence of C O bond in the structure, may be due to adsorbed CO 2 in the sample during FTIR measurements [31,32]. The sharp peak corresponding to ∼680 cm −1 can be ascribed to Si O bond, which exists in the form of SiO 3 .…”

Section: Fourier Transform Infrared (Ftir) Spectroscopymentioning

confidence: 97%

Cadmium silicate nanopowders for radiation dosimetry application: Luminescence and dielectric studies

Manohara¹,

Nagabhushana

Thyagarajan

et al. 2015

Journal of Asian Ceramic Societies

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a b s t r a c tPure cadmium silicate (CdSiO 3 ) nanophosphor was prepared by a low temperature solution combustion technique. In this technique, meso-structured silica was used as silica source. The prepared compounds were well characterized by powder X-ray diffraction (PXRD), scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared and UV-vis spectroscopic techniques. The PXRD peaks of as-formed sample are broad and amorphous in nature. The compound calcined at 800 • C shows pure monoclinic phase, which is the lowest temperature reported so far to obtain in this phase. The average crystallite size for phase pure compound was found to be ∼31 nm. The optical energy band gap of ∼5.6 eV was observed for the compound. Raman spectrum of the sample showed the all possible states of vibrational motions of the prepared samples. The UV irradiated samples with different dose and time with constant heating rate exhibit the thermoluminescence (TL) with a well resolved glow peak at ∼160 • C. The variation of TL intensity with dosage time results that the material was found to be quite useful in radiation dosimetry. The frequency dependent dielectric constant of the prepared sample exhibits high value at low frequency and vice versa.

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“…The cubic Gd 2 O 3 nanorods are an e±cient host system for doping the Eu 3þ ions compared to monoclinic GdOOH nanorods. 29 …”

Section: Preparation Of Europium-doped Gadolinium Hydroxide Nanorodsmentioning

confidence: 99%

Silica-Coated Europium-Doped Gadolinium Oxide Nanorods for Dual-Modal Imaging of Cancer Cells

Gayathri

Kumar

Panigrahi

et al. 2017

NANO

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Dual-modal imaging of cancer cells is possible with the silica-coated europium-doped gadolinium oxide nanorods due to their magnetic and luminescent properties. In the synthesized nanorods, europium ions serve as`luminescent centers' facilitating optical imaging and gadolinium oxide acts as the contrast agent for magnetic resonance imaging (MRI). This article reports the synthesis method of the europium-doped gadolinium oxide (Eu:Gd 2 O 3 Þ nanorods by the co-precipitation method. The prepared nanorods are further coated with silica to improve its biocompatibility. From the x-ray di®raction (XRD) data, the crystallinity was found to decrease due to the amorphous nature of the silica. Transmission electron microscopy (TEM) studies show that Eu:Gd 2 O 3 nanorods with a length of $ 600 nm and diameter of $ 40 nm were formed. Silica was coated uniformly with the thickness of $ 15 nm. Fourier transform infrared spectroscopy (FTIR) con¯rms the presence of silica in the prepared nanorods. Emission at 611 nm due the presence of Eu 3þ ions was observed. The life time of uncoated and silica-coated nanorods was calculated to be 1.1 ms and 0.9 ms, respectively. In vitro cytotoxicity of the synthesized nanorods in MG63 (human osteosarcoma cell line) was assessed by MTT assay. In vitro MRI studies reveal that the prepared nanorods can be used for T 1 contrast enhancement.

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Thermo and photoluminescence properties of Eu3+ activated hexagonal, monoclinic and cubic gadolinium oxide nanorods

Cited by 26 publications

References 41 publications

Synthesis, characterization, thermo- and photoluminescence properties of Bi3+ co-doped Gd2O3:Eu3+ nanophosphors

Synthesis, characterization, thermo- and photoluminescence properties of Bi3+ co-doped Gd2O3:Eu3+ nanophosphors

Cadmium silicate nanopowders for radiation dosimetry application: Luminescence and dielectric studies

Silica-Coated Europium-Doped Gadolinium Oxide Nanorods for Dual-Modal Imaging of Cancer Cells

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