In this study, we report, for the first time, on synthesis of lanthanum oxide [Formula: see text] nanoparticles NPs by laser ablation in water without using surfactant. The effect of laser wavelength on the optical and structural properties of [Formula: see text] NPs was investigated. X-ray diffraction studies show formation of polycrystalline lanthanum oxide with pure cubic phase and the crystallinity of the nanoparticles synthesized with [Formula: see text] nm was better than that prepared with [Formula: see text] nm. The optical absorption investigations reveal that a strong absorption peak at 234 nm was observed for [Formula: see text] NPs prepared at 532 nm laser wavelength. The optical energy gap of [Formula: see text] NPs synthesized with 532 and 1064 nm laser wavelengths were 5 and 4.5 eV, respectively. Scanning electron microscope (SEM) investigation indicated the formation of nanoparticles with average particle size of 35 nm for [Formula: see text] prepared with 532 nm and was 75 nm for [Formula: see text] prepared with 1064 nm laser wavelength. The effect of laser wavelength on the optoelectronic properties of hybrid In/p-[Formula: see text]/n-Si photodetector was studied. The responsivity studies of the photodetectors show the presence of two response peaks at 250 and 750 nm.

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In the early 90s military operations and United Nations Special Commission "UNSCOM" teams have been destroyed the past Iraqi chemical program. Both operations led an extensive number of scattered remnants of contaminated areas. The quantities of hazardous materials, incomplete destructed materials, and toxic chemicals were sealed in two bunkers. Deficiency of appropriate destruction technology led to spreading the contamination around the storage site. This paper aims to introduce the environmental detection of the contamination in the storage site area using geospatial analysis technique. The environmental contamination level of nutrients and major ions such as sulphate (SO 4), potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), chlorine (Cl), phosphate (PO 4) and nitrate (NO 3) were detected and analyzed. The grid soil samples on the site and surrounding areas have been investigated, analyzed, and compared to the background points. The storage area grid was divided into 30 major sectors and all samples were evaluated from acquires 10 samples from each sector. The detection results have indicated that SO 4 level was exceeded the permitted level by 25 times, K level also exceeded the permitted level but by 460, Na ions were 85 times greater the permitted level. Mg level was 180 times higher than that of permitted content. Activity level of Ca in the soil samples of the study area has also exhibited variability with nine times over the permitted level near the bunkers. However, very high contamination spot activity of Cl was found in destruction zone about which 44 times over the background level was found while PO 4 level exceeded the permitted level by 35 times over the permitted level and there was no activity detected for the nitrate in the storage area site.

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