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Abassi A.,Laboratoire Physico Chimie des Materiaux | Kallel N.,Laboratoire Physico Chimie des Materiaux | Kallel N.,Taibah University | Kallel S.,Laboratoire Physico Chimie des Materiaux | Pena O.,CNRS Chemistry Institute of Rennes
Journal of Superconductivity and Novel Magnetism | Year: 2014

The structural, magnetic and electrical properties of (La0.70−xNdx)Sr0.30Mn0.70Ti0.30O3 perovskites (0 ≤ x ≤ 0.30) prepared by the usual ceramic procedure were investigated. Structural Rietveld refinements of the X-ray powder diffraction revealed that for x = 0 the compound crystallizes in a rhombohedral (R3̄c) perovskite structure, while for x = 0.10, 0.20 and 0.30 the structure becomes orthorhombic (Pbnm). The field-cooled, zero-field-cooled and M(H) measurements lead to conclude that the samples with x≥0.10 behave like spin-glass systems. The temperature dependence of the resistivity exhibits two transitions at two temperatures Tp1 and Tp2, with the same width for the two peaks. TP1 results from the competition between double-exchange and super-exchange mechanisms inside the grain (intrinsic effects) whereas TP2 arises due to the grain boundary effects (extrinsic effect). The resistivity of this system seems to be related to the competition between antiferromagnetic insulating (AFI) phases, ferromagnetic insulating (FMI) phases and ferromagnetic metal (FMM) phases, which is induced by Nd doping effect. © 2014, Springer Science+Business Media New York. Source


Ammuri A.,Laboratoire Physico Chimie des Materiaux | Hejiouej S.,Laboratoire Physico Chimie des Materiaux | Ziat K.,Laboratoire Physico Chimie des Materiaux | Saidi M.,Laboratoire Physico Chimie des Materiaux
Journal of Materials and Environmental Science | Year: 2014

Two samples of Bi2O3 were synthesized by soft chemistry methods (co-precipitation and sol-gel). They were characterized by XRD and FTIR. The photo-degradation kinetics of Methyl Orange (MO), under UV irradiation, in an aqueous suspension at room temperature of Bi2O3 is studied as a function of the initial pH. The results obtained show that the oxide prepared by the sol-gel has very interesting properties and photo catalytic acidity environment improves the photo-degradation. Source


Skiker R.,Laboratoire Physico Chimie des Materiaux | Ammuri A.,Laboratoire Physico Chimie des Materiaux | Ziat K.,Laboratoire Physico Chimie des Materiaux | Saidi M.,Laboratoire Physico Chimie des Materiaux
Journal of Materials and Environmental Science | Year: 2015

Bi12TiO20/BiFeO3 heterostructures were successfully synthesized using coprecipitation method. The obtained powders were characterized by X-ray diffraction (XRD), Fourier Transform infrared (FTIR) and transmission electron microscopy (TEM). The prepared Bi12TiO20/BiFeO3 heterostructures showed high photocatalytic activity for the degradation of methyl orange (MO) in water under UV irradiation, compared to BiFeO3. The enhanced photocatalytic activity can be attributed to the formation of the heterostructure and to the efficient separation of electron-hole pairs and/or to the particle size. Source

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