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CuInS2–ZnO nanocomposites were prepared by two combined approaches, namely solvothermal and chemical precipitation. The structure, morphology, composition and optical properties of the nanocomposites was studied by X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and diffuse reflectance spectroscopy (DRS). The influence of ZnO content on the photocatalytic activity of these nanocomposites was studied. The results showed that CuInS2-ZnO samples possess photocatalytic activity against a Rhodamine B (RhB) synthetic solution. Additionally, electron spin resonance spectroscopy (ESR) coupled with spin trapping technique was used to characterize the reactive oxygen species (ROS). The photocatalytic mechanism was discussed according to ROS generation that were able to degrade the RhB. The photodegradation rate for RhB removal by CuInS2–ZnO nanoparticles increased with the addition of ZnO nanoparticles on their surface. During the irradiation, both hydroxyl radical (OH−) and superoxide anion (O2−) were highlighted suggesting that the CuInS2–ZnO nanocomposites are suitable for use in water depollution by photocatalysis. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sn1 − x V x O2 nanoparticles annealed at different temperatures were prepared. [•] The crystallites sizes were estimated by XRD. [•] V2O5 phase was evidenced by Raman spectroscopy in samples annealed at 800, 1000°C. [•] A ferromagnetic behaviour for the undoped SnO2 sample was obtained. [•] The ferromagnetism is enhanced by doping with V ions and annealing at 450°C. [ABSTRACT FROM AUTHOR]

Abstract: xTiO2∙(1−x)[P2O5·CaO] glass system, with x ranging from 0.5 to 15mol%, was prepared and the effect of modifier ion on spectroscopic properties with the help of optical absorption, photoluminescence, electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) was examined. Optical absorption and EPR spectra have indicated that titanium ions exist in Ti3+ state while photoluminescence spectra exhibited an emission band at about 415nm, which could be the result of the charge transfer band of Ti4+ ions. XPS spectroscopy studies have revealed that titanium ions exist in two oxidation states: 3+ and 4+. An analysis concerning the Ti3+ ions contents in these glasses was carried out. [Copyright &y& Elsevier]

Abstract: This paper report the results obtained by EPR and Raman investigations of xMoO3⋅(100− x)[P2O5⋅CaO] with 0⩽ x ⩽50mol% glass system. From EPR spectroscopy were evidenced the local symmetry and the interaction between Mo5+ ions. Depending on the content of MoO3 were highlighted the EPR spectra modifications. By Raman spectroscopy were identified and analyzed the modification which appear on the characteristic bands of these glasses. At low concentration of molybdenum oxide the specific Raman bands of long phosphate chains (Q2) dominate the spectra meanwhile for high molybdenum content the most intense bands are those specific to MoO3 and short phosphate groups. From both techniques we can conclude that at low concentration of molybdenum oxide, it acts as a very strong network modifier while for high concentrations it plays the role of network co-former. [Copyright &y& Elsevier]

Abstract: This article reports the effects of the annealing temperature on the structural, morphological and spin dynamic properties of SnO2 samples doped with 0.005Mn. The samples were annealed at 400, 600, 700 and 800°C and analyzed by XRD, TEM, XPS and EPR spectroscopy. The XRD spectra show that the average crystallite size increases with the increase of the annealing temperature. The particles size and morphology were characterized by TEM microscopy. The valence bands of Mn were investigated by measuring the XPS spectra of Mn 2p core-level doublet. Regardless of the annealing temperature, the observed EPR spectra are due to (i) Mn2+ ions either interstitially situated on the particle surfaces or isolated ones located substitutionally at Sn sites and (ii) Mn4+ ions which substitute for Sn4+ in SnO2 lattice. The effects of the annealing temperature on the relative fractions of Mn2+ and Mn4+ ions are presented and discussed. In Sn1− x Mn x O2 (x =0.005) sample annealed at 400°C, a FMR line was identified and attributed to a ferromagnetic phase. [Copyright &y& Elsevier]

Structural, morphological and EPR investigations on Zn1-xMnxO fine ceramics (x = 0.01 and 0.03) are reported. XRD studies reveal a wurzite-type structure, while the formation of ZnMnO3 secondary phase was evidenced only for x = 0.03 sample. Both EPR spectra present a hyperfine structure specific to isolated Mn2+ ions and for the sample x = 0.03, a new quite broad resonance line arises, which could be attributed to a ferromagnetic phase. [ABSTRACT FROM AUTHOR]

Electron magnetic resonance (EMR) investigations of SnFeO ( x = 0.07) powders annealed at different temperatures are reported. EMR spectra show the presence of both the isolated paramagnetic Fe ions incorporated into the SnO lattice and a ferromagnetically ordered component. By increasing the annealing temperature, the EMR spectrum attributed to the ferromagnetically coupled Fe ions diminishes probably due to the migration of Fe ions and the formation of the second phase. The presence of the second phase was evidenced by X-ray diffraction measurements. [ABSTRACT FROM AUTHOR]

We report an electron paramagnetic resonance (EPR) investigation of the spin dynamics in the paramagnetic regime of nanosized La0.67Ca0.33MnO3−δ manganites. The temperature dependences of the EPR line width and integral intensity have been analyzed in terms of the bottlenecked spin relaxation and small polaron hopping scenarios. The exchange coupling integral between Mn3+ and Mn4+ ions and the polaron activation energy decrease with the reduction of grain size. A discussion is given concerning the factors which could explain the observed changes. [ABSTRACT FROM AUTHOR]