Optical emission, vibrational feature, and shear-thinning aspect of Tb3+-doped Gd2O3 nanoparticle-based novel ferrofluids irradiated by gamma photons

Abstract

The present work reports on the spectroscopic and rheological properties of un-exposed and gamma (γ-) irradiated rare earth (RE) oxide nanoparticle-based ferrofluids (FFs). The FFs were produced by dispersing surfactant coated terbium (Tb3+)-doped gadolinium oxide (Gd2O3) nanoparticles in the ethanol medium and later on they were subjected to energetic γ-irradiation (1.25 MeV) at select doses (97 Gy and 2.635 kGy). The synthesized RE oxide nanoparticles were of ∼7 nm size and having a cubic crystal structure, as predicted from transmission electron microscopy and x-ray diffraction studies. Fourier transformed infra-red (FT-IR) spectra showed an adequate blue shift of the Gd-O vibrational stretching mode from a wavenumber value of ∼558 cm−1, for the un-irradiated sample to a value of ∼540 cm−1 corresponding to the irradiated sample (2.635 kGy). In contrast, photoluminescence spectra have revealed modification of defect states along with Tb3+ assisted radiative transitions. The rheology measurements have illustrated unusual shear thinning behavior of the FFs, with an apparently improved power index (s) value from 0.34 to 0.50, obtained for increasing γ-dose cases. The variation of the decay parameter with irradiation dose, as predicted from the nature of apparent viscosity curves, is attributed to the defect formation, role of impurity ions (Tb3+), and weakening of inter nanoparticle bonding. The unusual properties of the novel RE oxide based FFs may find scope in sealing and shielding elements in the radiation environment including accelerator and other related zones.

Evaluation of a quercetin–gadolinium complex as an efficient positive contrast enhancer for magnetic resonance imaging

“…Bands at 553-465 cm À1 are due to the presence of n(Gd-O) stretching vibrations, indicating the formation of metal complex, whereas these bands were absent in the FTIR spectrum of the ligand quercetin. 26 The n(C-O-C) frequency and n ring (C]O) (i.e., C ring, Fig. S1, ESI †) frequencies exhibit a shi towards the lower energy.…”

Perceptible exciton-to-trion conversion and signature of defect mediated vibronic modes and spin relaxation in nanoscale WS2 exposed to γ-rays

“…To be specific, synthesis of silver and gold nanoparticles have been ensured under γ-radiation environment [17,18]. Similarly, remarkable improvement in optical, magneto-optic and shear thickening features have been witnessed in oxide based nanosystems [19,20]. Conversely, γ-photon induced modification of vibrational modes have been realized in few-layered graphitic systems [21].…”

Amine Functionalized Gadolinium Oxide Nanoparticles-Based Electrochemical Immunosensor for Cholera

“…Gd 2 O 3 NPs showed very high fluorescence at 462 nm when excited by a230 nm wavelength (Figure 3c). The peak maxima near 462 nm could be attributed to surface defects on NPs of Schottky and Frenkel type [24].…”