TY - CONF A1 - Gornushkin, Igor B. T1 - Modeling Equilibrium Chemistry in Laser Induced Plasmas and Plasma Chemical Reactors N2 - A brief introduction will be given on modeling chemical reactions in laser induced plasmas using stoichiometric and non-stoichiometric approaches. Several applications will be considered, which can benefit from such modeling. Those include plasma enhanced chemical vapor deposition (PECVD), surface modification and surface coating, and molecular analysis by LIBS. Each application will be illustrated by simulations of relevant chemical systems. For PECVD, chemical systems are BCl3/H2/Ar, BF3/H2/Ar, BCl3/BF3, Mo/BF3/H2; for surface modification/coating it is Ti/air; for molecular LIBS they are CaCO3/Ar, Ca(OH)2/Ar, and CaCl2/Ar. Advantages and shortcomings of equilibrium chemical hydrodynamic models of laser induced plasmas will be discussed. T2 - 1st NIP Conference National Institute of Physics (IKF), the Albanian Academy of Sciences CY - Online meeting DA - 10.02.2022 KW - Laser ablation KW - Laser induced plasma deposition KW - Surface coating KW - Titanium dioxide KW - Emission spectroscopy KW - Hydrodynamic model KW - Plasma chemistry PY - 2022 AN - OPUS4-54328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Plasma Fundamentals and Diagnostics N2 - This course will provide an introduction to plasma diagnostic techniques. The major focus of the course will be on the discussions of the practical procedures as well as the underlying physical principles for the measurements of plasma fundamental characteristics (e.g., temperatures and electron number density). Particular emphasis will be placed on laser induced plasma–atomic emission spectrometry, but other analytical plasmas will also be used as examples when appropriate. Selected examples on how one can manipulate the operating conditions of the plasma source, based on the results of plasma diagnostic measurements, to improve its performance used for spectrochemical analysis will also be covered. Topics to be covered include thermal equilibrium, line profiles, temperatures, electron densities, excitation processes, temporal and spatial resolution. T2 - 2022 Winter Conference on Plasma Spectrochemistry CY - Tucson, Arizona, USA DA - 17.01.2022 KW - Thermal equilibrium KW - Excitation processes KW - Electron number density KW - Temperatures KW - Spatial information KW - Emission line profiles PY - 2022 AN - OPUS4-54288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Deposition of Titanium Oxides by Nanosecond Laser Ablation: Simulation and Experiment N2 - Surface modification of titanium by laser ablation is investigated theoretically and experimentally. The modification consists in texturing the surface and redeposition of chemically transformed material from the ablation plasma. The redeposition is driven by the hydrodynamic flow in the plasma. Such surface modification improves the biocompatibility of titanium implants. T2 - 2022 Winter Conference on Plasma Spectrochemistry CY - Tucson, Arizona, USA DA - 17.01.2022 KW - Laser ablation KW - Laser induced plasma deposition KW - Surface coating KW - Titanium dioxide KW - Emission spectroscopy KW - Hydrodynamic model KW - Plasma chemistry PY - 2022 AN - OPUS4-54289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kornev, R. A. A1 - Sennikov, P. G. A1 - Gornushkin, Igor B. A1 - Ermakov, A. A. A1 - Shkrunin, V. E. A1 - Polykov, V. S. A1 - Kornev, A. R. A1 - Kornev, K. D. T1 - Laser induced dielectric breakdown as a novel method for the synthesis of molybdenum boride JF - Plasma chemistry and plasma processing N2 - Laser induced dielectric breakdown (LIDB) on a surface of solid Mo in H2/BF3 atmosphere at 30-760 Torr and in a gaseous mixture MoF6/H2/BF3 + at 760 Torr pressure is tested for synthesis and deposition of superhard molybdenum borides that are needed in many areas of industry and technology. The emission spectra of the plasma and the dynamics of the gas discharge near the substrate are investigated. A comparative analysis of the gas mixture before and after exposure to LIDB plasma is carried out using IR spectroscopy. The conditions for the formation of molybdenum borides are determined. A thermodynamic analysis of the MoF6/H2/BF3 and Mo/H2/BF3 systems is carried out to determine the temperature range for the formation of molybdenum borides and establish the main chemical reactions responsible for their formation. Deposits containing MoB and MoB2 phases are obtained. For the mixture MoF6/H2/BF3, the deposit exhibits an amorphous layered structure, which contains 19.15 wt% F, 30.45% O, and 0.8% Si. For the Mo/H2/BF3 system at the pressures 30 and 160 Torr, nanopowder of molybdenum boride is produced with a characteristic grain size of 100 nm. At pressures above 160 Torr, Mo nanopowder with a grain size <30 nm is obtained. KW - LIDB plasma KW - MoF6 KW - BF3 KW - Hydrogen reduction KW - Molybdenum boride PY - 2022 DO - https://doi.org/10.1007/s11090-021-10224-0 SN - 1572-8986 SP - 1 EP - 18 PB - Springer CY - Dordrecht AN - OPUS4-54290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Multifaceted laser induced plasma: spectroscopy and beyond N2 - In this presentation, I will give a brief overview of my personal experience with laser induced plasma (LIP). I will start from my and colleagues’ early works, where we used LIP as an atomic reservoir for laser induced fluorescence (LIP). We applied LIP-LIF for a sensitive detection of trace elements in various materials and demonstrated that under certain conditions the technique can even be used for isotope analysis. Next, I will discuss the application of LIP spectroscopy, i.e., LIBS, to material identification that nowadays constitutes one of the best applications of this technique. In those early days, we used correlation analysis for spectra processing; it is now replaced by more powerful chemometric methods. Further, I will stop on our efforts in modeling LIP that we first intended for the improved quality of spectroscopic analysis and later extended to non-spectroscopic fields such as chemical vapor deposition and surface structuring. We developed a version of calibration-free LIBS, in which we iterated model-generated spectra until a close match was achieved between experimental and synthetic spectra to determine concentrations. Next, I will briefly overview our recent developments in plasma modeling that include plasma chemistry. This was important in view of widening application of LIBS as a molecular technique. I will also address several plasma diagnostics, e.g., Radon transform tomography that we developed to get more insight about LIP that was helpful for both analytic spectroscopy and modeling. Finally, I will mention several exotic applications of LIP such as LIP-based lasers and chemical reactors to illustrate a real multifaceted character of laser induced plasma and usefulness of its study for many science fields. T2 - SciX 2022, The Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) CY - Cincinnati, OH, USA DA - 02.10.2022 KW - Emission spectroscopy KW - Laser ablation KW - Laser induced plasma deposition KW - Surface coating KW - Hydrodynamic model KW - Plasma chemistry PY - 2022 AN - OPUS4-55968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - A Long Way of Plasma Modeling: Personal Experience N2 - Modeling is an important tool for understanding a physical phenomenon. It helps to interpret results of experiments and optimize experimental parameters for obtaining a desirable result. Modeling laser induced plasma is beneficial for many scientific and industrial fields, e.g., analytical chemistry, pulsed laser deposition, plasma enhanced chemical vapor deposition, laser welding, additive manufacturing etc. In this presentation, a personal experience in development of a physical model of laser induced plasma will be given in a chronological sequence starting from early 2000th and until now. Over the time, the model evolved from its simple analytical form that described plasma emission spectra to its current numerical form that describes plasma dynamics, chemistry, and interaction with a substrate surface. Several examples will be given for the application of the model to practical problems such as spectroscopic chemical analysis, plasma enhanced chemical vapor deposition, and surface modification by laser ablation. T2 - XII World Conference on Laser Induced Breakdown Spectroscopy CY - Bari, Italy DA - 05.09.2022 KW - Laser induced plasma KW - CFD computational fluid dynamic KW - Plasma modeling KW - Plasma chemistry PY - 2022 AN - OPUS4-55669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gornushkin, Igor B. A1 - Völker, Tobias T1 - Intrinsic Performance of Monte Carlo Calibration-Free Algorithm for Laser-Induced Breakdown Spectroscopy JF - Sensors N2 - The performance of the Monte Carlo (MC) algorithm for calibration-free LIBS was studied on the example of a simulated spectrum that mimics a metallurgical slag sample. The underlying model is that of a uniform, isothermal, and stationary plasma in local thermodynamical equilibrium. Based on the model, the algorithm generates from hundreds of thousands to several millions of simultaneous configurations of plasma parameters and the corresponding number of spectra. The parameters are temperature, plasma size, and concentrations of species. They are iterated until a cost function, which indicates a difference between synthetic and simulated slag spectra, reaches its minimum. After finding the minimum, the concentrations of species are read from the model and compared to the certified values. The algorithm is parallelized on a graphical processing unit (GPU) to reduce computational time. The minimization of the cost function takes several minutes on the GPU NVIDIA Tesla K40 card and depends on the number of elements to be iterated. The intrinsic accuracy of the MC calibration-free method is found to be around 1% for the eight elements tested. For a real experimental spectrum, however, the efficiency may turn out to be worse due to the idealistic nature of the model, as well as incorrectly chosen experimental conditions. Factors influencing the performance of the method are discussed. KW - Laser induced breakdown spectroscopy KW - Calibration-free analysis KW - Monte Carlo algorithm PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558016 DO - https://doi.org/10.3390/s22197149 VL - 22 IS - 19 SP - 7149 PB - MDPI AN - OPUS4-55801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Gornushkin, Igor B. T1 - Importance of physical units in the Boltzmann plot method JF - Journal of Analytical Atomic Spectrometry N2 - The Boltzmann plot is one of the most widely used methods for determining the temperature in different types of laboratory plasmas. It operates on the logarithm as a function of the dimensional argument, which assumes that the correct physical units are used. In many works using the Boltzmann method, there is no analysis of the dimension of this argument, which may be the cause of a potential error. This technical note offers a brief description of the method and shows how to correctly use physical units when using transcendental functions like the logarithm. KW - Boltzmann plot KW - Laser induced plasma PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558039 DO - https://doi.org/10.1039/d2ja00241h SP - 1 EP - 3 PB - Royal Society of Chemistry AN - OPUS4-55803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Kornev, R. A. A1 - Veiko, V. P. T1 - Molecule formation in reactive LIBS plasmas: model and experiment N2 - Formation and detection of molecules in laser induced plasmas (LIP) is a hot topic. In analytical plasmas like LIBS, the detection of molecules is important for identification of geological and other materials, analysis of isotopes and difficult elements (Cl, F, etc.) via molecular emission. In chemical plasmas, like PECVD (plasma enhanced chemical vapor deposition) or PLD (pulsed laser deposition), molecules formed in the plasma determine a composition and a thickness of deposits. Similarly, molecules play an important role in microstructuring and oxidizing metal surfaces by laser ablation. It is unfortunate that different communities, which utilize plasma methods and seek for solutions of similar problems, do not strongly overlap, and do not fully use knowledge accumulated by each other. In this presentation, mechanisms of formation of molecules will be analyzed on the example of LIPs used for chemical vapor deposition and metal microstructuring. Theoretical analysis includes equilibrium chemistry calculations combined with plasma hydrodynamics. First, LIP excited in a gas mixture of BCl3 or BF3 with H2 or CH4 will be analyzed; this chemical system is used for obtaining deposits of refractory solid boron and boron carbide. Second, a breakdown in the SiF4 + SiCl4 gas mixtures will be described; this method allows synthesis of fluorochlorosilanes SiFxCl4-x (x = 1, 2, 3), the good etching agents (Figure). Third, solid ablation of Mo in BF3+H2 and Ti in air will be considered aimed at obtaining deposits of high hardness MoxBy and films of TixOy on textured Ti surfaces, correspondingly. In experiment, reaction gases before and after laser illumination, and solid deposits are analyzed by optical emission spectroscopy (OES), IR and mass spectrometry (MS), SEM, X-ray, and AFM. It will be shown that the hydrodynamic-chemical model adequately predicts the composition of LIPs, zones of molecular formation, dependence on reactant stoichiometry, plasma temperature and pressure. T2 - Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy CY - Gijon, Spain DA - 29.11.2021 KW - Laser induced plasma KW - Plasma chemistry KW - Molecules formation KW - Plasma enhanced chemical deposition PY - 2021 AN - OPUS4-53850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - model of laser induced plasma relevant to structuring and coating of titanium implants N2 - The presentation will give a brief overview of the processes occurring in laser-induced plasma and methods of modeling these processes. In particular, a chemical-hydrodynamic model will be considered, which is related to the modification of the surface of metallic titanium by laser pulses. The details and simplifications of this model, its shortcomings and the possibilities of their elimination will be discussed. This model is related to the structuring of the surface of dental implants with a laser and the deposition of an oxide film on it. T2 - THE 2-nd THEMATIC INTERNATIONAL SCIENTIFIC AUTUMN SCHOOL ON LASER MICRO- & NANOTHECHNOLOGIES: 2021 – BIOMEDICAL TECHNOLOGIES CY - St. Petersburg, Russia DA - 09.11.2021 KW - Laser ablation KW - Laser induced plasma deposition KW - Surface coating KW - Emission spectroscopy KW - Hydrodynamic model KW - Plasma chemistry PY - 2021 AN - OPUS4-53718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -