Manganese-Nanoparticles Substitutions on the Vanadium Sites of Bi-Sr-Vanadate Aurivillius Ceramics

The aurivillius phase of Mn-substituted samples with general formula Bi2SrV2−MnO9, where =0.05,0.1,0.2,0.3, and 0.6 mole were prepared by solid-state reaction technique and ceramics procedures. The X-ray structural measurement analysis confirmed the formation of single-phase-layered hexagonal structure which is observed in all samples. The thermal stability and phase change of the green powders were studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). SEM revealed that the average grain size increases with increasing Mn content. The infrared absorption spectra recorded a series of vibrational modes within the range of 400–1600 cm−1 were investigated. The present work also studied the effect of Mn-doping concentration interactions on both DC-electrical conductivity and ESR spectra

Synthesis, Characterization and Effect of ?-Ray on Rare-Earth Tb3+ Doped Nano LiMn2-xTbxO4 Lithium Manganates

Pure nano lithium manganese oxide spinel (LiMn2O4) and doped Tb3+ lithium manganese oxide spinel, [LiMn2-xTbxO4, (x = 0.01%, 0.02%)], are synthesized via solid-state method. The synthesized LiMn1.99Tb0.01O4 was irradiated by ?-irradiation with 30 kGy. The resulting spinel product is characterized by various methods such as thermo gravimetric and differential thermal analysis (TG/DTA), infrared (IR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive of x-rays analysis (EDAX), electron spin resonances (ESR) studies and DC–electrical conductivity measurements. The XRD and SEM confirm the nano materials size for all prepared samples. DC–electrical conductivity measurements indicates that these samples are semiconductor and the activation energy decreases with increasing rare-earth Tb3+ content; ?Ea= 0.427 eV for LiMn1.99Tb0.01O4, ?Ea= 0.339 eV for LiMn1.98Tb0.02O4 and decreases to ?Ea= 0.330 eV for ?-irradiation of LiMn1.99Tb0.01O4 nano spinel thus in role increases its attractiveness in modern  electronic technology. Abou-Sekkina activation energy for the induced ?-irradiation is evaluated for the first time, which was found to be 0.097 eV. Keywords: Nano lithium manganates, Tb3+ doping spinel, ? –Ray effec