Hossein Moradi

HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF STRAW BUNDLE-LIKE LITHIUM SODIUM DISILICATE (SILINAITE) MICRO-RODS

Highly mono-shaped straw bundle-like silinaite micro-rods have been synthesized using an aqueous mixture of silicic acid, lithium sulfate, and sodium hydroxide under hydrothermal conditions at 180°C. The synthesized materials were characterized by powder X-ray diffraction technique and Fourier transform infrared spectroscopy. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy technique. The synthesized micro-rods are composed of long, fine nanosheets. Electronic absorption and photoluminescence spectra of the synthesized materials were also studied. With increasing reaction time, a blueshift was observed in the UV–vis electronic absorption and emission spectra of the synthesized materials.

Sol–gel synthesis, characterization, and optical properties of Gd3+-doped CdO sub-micron materials

Highly crystalline Gd3+-doped cadmium oxide micro-structure was synthesized by calcining the obtained precursor of a sol–gel reaction. The reaction was carried out with cadmium nitrate (Cd(NO3)2·4H2O), gadolinium oxide, and ethylene glycol (C2H6O2) reactants without any additives at 80°C for 2 h. The resulting gel was calcined at 900°C with increasing temperature rate of 15°C/min for 12 h in a furnace. As a result of heating, the organic section of the gel was removed, and the Gd3+-doped cadmium oxide micro-structure was produced. The obtained compound from the sol–gel technique possesses a cubic crystalline structure at a micro scale. XRD study indicates that the obtained Gd3+-doped CdO has a cubic phase. Also, the SEM images showed that the resulting material is composed of particles with cluster structure. Also, FT-IR spectroscopy was employed to characterize the Gd3+-doped CdO micro-structures.

Hydrothermal synthesis and investigation of optical properties of Nb5+-doped lithium silicate nanostructures

The hydrothermal synthesis and optical properties of Nb5+-doped lithium metasilicate and lithium disilicate nanomaterials were investigated. The microstructures and morphologies of the synthesized Li2−2xNb2xSiO3+δ and Li2−2xNb2xSi2O5+δ nanomaterials were studied with powder X-ray diffraction and scanning electron microscopy techniques, respectively. The synthesized niobium-doped lithium metasilicate and lithium disilicate nanomaterials, respectively, are isostructural with the standard bulk Li2SiO3 (space group Cmc21) and Li2Si2O5 (space group Ccc2) materials. Photoluminescence spectra of the synthesized materials are studied. The measured optical properties show dependence on the dopant amounts in the structure.

Development and Decline of the Bampur Valley, Based on the New Archaeological Evidence from Prehistoric Period

This paper consists of some of the findings of the authors during their research at prehistoric sites of Bampur and its surrounding areas in August 2011. These areas, which have been introduced as Bampur-related sites, comprise an area about of 5–10 kilometers and belong to the Bronze Age. The paper introduces, categorizes and analyzes the archaeological findings in relation to the Bampur collection. The archaeological findings show that: (1) unlike the previous belief, there existed a peak settlement dated back to the Chah Husseini period which was prior to Bampur I; (2) in fact, Bampur II–IV had larger populations due to growth of trade and commerce and their relations with Yahya and Mesopotamia; (3) the later periods of the Bampur collection show a decreasing number of sites at Bampur VI.