Elemental analysis of materials including silicon (100) and (111) crystals with single and double pulsed LİBS

Download
2012
Yurdanur Taşel, Elif
Laser Induced Breakdown Spectroscopy (LIBS) which is used to determine the elemental content of various samples, inspects the emission spectroscopy of samples of interest for searching certain elements or identifying the unknown content. In this study, spectroscopic analyses of various kinds of metals, namely, Cu, Fe, Mo, Ti, W, some compounds such as CuBe, ZnSe, ZnS, GaSe, some semimetals like Si, Ge and even gases were investigated by means of a compact-commercial portable LIBS system and an independently constructed experimental set-up consisting of a single pulse system and various kinds of double pulse configurations using Nd:YAG lasers. The contributions of this thesis to the LIBS community can be classified into two main groups- which are experimental and code development. One of the experimental contributions was the investigation of the different crystal surfaces of silicon in which dangling bond density were taken into account for a more precise comparison of atomic emissions. The second experimental contribution was the polarization experiments by which polarization dependency, to some extent, was demonstrated. The third and final one was the orthogonal double pulse configuration with a 45 o incidence angle for both lasers in opposite directions by which it was shown that the positioning becomes straightforward yielding the desired reproducible results. The second major contribution was to develop a basic code for analyzing the experimental data more accurately. In conclusion, by means of the different experimental approaches, factors relating to the enhancement in intensity were investigated and as a result of developing the code, flexibility in upgrading the constraints of element searching was obtained and the updating of the database was accomplished.

Suggestions

Kinetic analysis of DSC and thermogravimetry data for combustion of lignite
Kök, Mustafa Verşan (1996-06-01)
Thermal analysis increasingly being used to obtain kinetic data relating to sample decomposition. This work involves a comparative study of several methods used to analyse DSC and TG/DTG data obtained on the oxidation of Beypazari lignite. A general computer program was developed and the methods are compared with regard to their accuracy and the ease of interpretation of the kinetics of thermal decomposition. For this study, the ratio method was regarded as the preferred method, because it permits the estim...
Kinetic analysis of DSC and thermogravimetric data on combustion of lignite
Kök, Mustafa Verşan (Springer Science and Business Media LLC, 1996-06-01)
Thermal analysis increasingly being used to obtain kinetic data relating to sample decomposition. This work involves a comparative study of several methods used to analyse DSC and TG/DTG data obtained on the oxidation of Beypazari lignite. A general computer program was developed and the methods are compared with regard to their accuracy and the ease of interpretation of the kinetics of thermal decomposition. For this study, the ratio method was regarded as the preferred method, because it permits the estim...
Thermal Characterization of Sepiolite Samples
Kök, Mustafa Verşan (2013-01-15)
In this research, two sepiolite samples of different origins were studied by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimeter, and thermogravimetry. It was observed that both sepiolite samples are nearly pure and well crystallized sepiolite. Thermal studies (thermogravimetry) showed that four distinct weight loss regions are observed in both sepiolite samples studied. It was noticed that these structural changes play an important role to the properties and uses o...
Ion implantation and deposition on the inner surfaces of cylinders by exploding metallic foils
Demokan, O (2000-10-01)
A novel scheme for ion deposition and possibly ion implantation on the inner surfaces of cylindrical targets is proposed and experimentally tested. A large current is passed through a coaxial table-type structure, composed of a straight conductor and a thin metallic foil, surrounding it. The foil evaporates and ionizes forming a metallic plasma, which is pushed radially outward due to the pressure of the magnetic field, confined to the region between the plasma and the conductor. The ions of the foil materi...
Kinetic analysis of in situ combustion processes with thermogravimetric and differential thermogravimetric analysis and reaction tube experiments
Kök, Mustafa Verşan (1995-01-01)
This research comprises the determination of kinetic parameters of in situ combustion processes by reaction tube and thermal (thermogravimetric analysis (TGA)/differential thermogravimetric analysis (DTGA)) experiments. A previously developed laboratory model and a Du Pont 9900 thermalanalyzer unit were used to run the experiments. Three reaction regions for combustion of crude oil in porous media were observed in the reaction tube and TGA/DTGA experiments and are defined as low temperature oxidation, fuel ...
Citation Formats
E. Yurdanur Taşel, “Elemental analysis of materials including silicon (100) and (111) crystals with single and double pulsed LİBS,” Ph.D. - Doctoral Program, Middle East Technical University, 2012.