EPR study of fluorite containing different concentration of ceria

Aminov, L. K.; Kurkin, I. N.; Lovchev, A V; Rakhmatullin, R. M.; Родионов, А. А.; Korableva, S. L.

doi:10.1016/j.matchemphys.2019.122136

Cited by 2 publications

(1 citation statement)

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“…It is difficult to synthesize very small Ceria NPs and have a narrow distribution sizes. For the little bit larger size of Ceria NPs, EPR, EDS, Raman (RA analysis), and XRD (X-ray Diffraction), distortions of Ceria NPs with defects inside the oxide lattice [33][34][35][36][37][38][39] have showed. But in case of Bulk ceria, H atoms don't have at a high symmetry position but instead move toward the O sites forming hydroxyl species [40].…”

Section: Introductionmentioning

confidence: 99%

EPR Study of CeO<sub>2</sub> Nano Particles

Uthra

Sharma

2022

MSF

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In this paper, we have studied the EPR spectra, X-ray diffraction and Raman Analysis, Microstructures-morphology of the Ceria NPs calcined at different temperatures of 700 °C, 850 °C ,these materials have been synthesized by Co precipitation (CPT) method by using Cerium tri-nitrate hexahydrate and potassium carbonate solutions. Then synthesized precipitate was heated at 70 °C for 20 hour. Slow grinding of the precipitate and calcined for 3 hours at different temperatures viz. 700 °C and 850 °C to form fine Cerium oxide powder-Ceria NPs. The EPR measurements were made using continuous wave spectrometer (X-band, Bruker Biospin EMX Plus). The g values were obtained by using diphynelpirichylhydrageyl (DPPH-C18H12N5O6) sample and got g value is around 1.97. This g tensor is decreased when the calcined temperature are increased, EPR parameters are also changed as the calcined temperature increases. When the calcined temperature is increased from 700 °C to 850 °C, a doublet separated, intensity increased. The X-Ray diffraction pattern shows the nature of the Ceria NPs crystal, with a cubic structure and got the lattice parameters 5.392 Å for samples calcined at temperature of 700 °C and 5.357 Å at 850 °C which shows decreasing trend in lattice parameter with calcination temperature. The intensity of Raman peaks is also shifted upwards with a rise in temperature. This intensity difference could be because of the rise in vibrational amplitudes of the closest neighboring bonds because of the increase in particle size 11.3± 1.0 to 15.6± 1.0 nm at calcination temperatures of 700 °C and 850 °C and the Raman peak of peak I, 461 cm-1 and peak II, 463 cm-1 respectively. Other peaks were not observed in this Raman pattern. The EDS analysis confirms the presence of the Ce and O atoms in the synthesized samples. Spherical shapes and homogeneously distributed Ceria NPs and a rather tendency for agglomeration were confirmed.

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