Imran Rehan

Determination of toxic and essential metals in rock and sea salts using pulsed nanosecond laser-induced breakdown spectroscopy

A spectrometer based on pulsed nanosecond laser-induced breakdown spectroscopy (LIBS) was employed for the quantitative determination of heavy and essential metals in salts from various sources available in Pakistan. Six salt samples were collected from sea salt and rock salt. Toxic metals (Cu, Cd, and Ni) and other microessentials (Fe, Ca, Co, Mg, Mn, S, and Zn) were investigated from the recorded spectra. The detection system was calibrated using a parametric dependence study. The quantitative analyses were accomplished under the assumption of local thermodynamic equilibrium and optically thin plasma. The results by the LIBS technique were in agreement with the outcomes of the same samples studied using a more standard approach like inductively coupled plasma-atomic emission spectroscopy (ICP-AES). When the concentrations of heavy and essential metals were calculated using a calibration-free LIBS method that does not need a standard salt specimen and dilution, both LIBS and ICP-AES were also in good agreement. The limit of detection of the experimental set up was determined for the observed heavy metals in the studied samples.

Determination of Metals Present in Textile Dyes Using Laser-Induced Breakdown Spectroscopy and Cross-Validation Using Inductively Coupled Plasma/Atomic Emission Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was used for the quantitative analysis of elements present in textile dyes at ambient pressure via the fundamental mode (1064 nm) of a Nd:YAG pulsed laser. Three samples were collected for this purpose. Spectra of textile dyes were acquired using an HR spectrometer (LIBS2000

Tunability of morphological properties of Nd-doped TiO2 thin films

In this work, an endeavor is made toward structural assessment and morphological variation of titanium dioxide (TiO2) thin films when doped with neodymium (Nd). The electron beam deposition technique was employed to fabricate Nd-based TiO2 thin films on n-Type Si substrates. Nd concentration was varied from 0.0 to 2.0 atomic percent (at.%) under identical growth environments. The films were deposited in an oxygen-deficient environment to cause the growth of rutile phases. Energy dispersive x-ray spectroscopy confirmed the presence and variation of Nd dopant in TiO2. X-ray diffraction analysis showed the transformation of amorphous structures of the as-grown samples to anatase polycrystalline after annealing at 500 °C, while atomic force microscopy exposed linearity in grain density in as-grown samples with doping until 1 at.%. Raman spectrums of as-grown and annealed samples revealed the growth of the anatase phase in the annealed samples. Based on these results it can be proposed that Nd doping has pronounced effects on the structural characteristics of TiO2 thin films.