Optical emission spectroscopic studies on laser ablated TiO 2 plasma (original) (raw)

Optical emission spectroscopy and modeling of plasma produced by laser ablation of titanium oxides

Spectrochimica Acta Part B: Atomic Spectroscopy, 2001

In the present study, the time evolution of electron number density, of electron, atom and ion temperatures, of plasma produced by KrF excimer laser ablation of titanium dioxide and monoxide targets, are investigated by temporally and spatially resolved optical emission spectroscopy over a wide range of laser fluence from 1.7 to 6 J cm y2 , oxygen pressures of 10 y2 ᎐10 y1 torr and in a vacuum. A state-to-state collisional radiative model is proposed for the first time to interpret the experimental results at a distance of 0.6 mm from the target surface, in vacuum and for a time delay from 100 to 300 ns from the beginning of the laser pulse. In particular, we concentrate our attention on problems concerning the existence of the local thermodynamic conditions in the laser-induced plasma and deviation from them, as observed in our experiment. The numerical model proposed for calculating the electron number density and the population densities of atoms and ions in excited states give good quantitative agreement with the experimental results of the optical emission spectroscopy measurements. ᮊ

Spectral Characterization of Laser Induced Plasma from Titanium Dioxide

Plasma Science and Technology, 2007

Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity.

Plasma spectroscopy of titanium monoxide for characterization of laser ablation

Journal of Physics: Conference Series

Ablation of titanium wafers in air is accomplished with 60 µs pulsed, 2.94 µm laser radiation. Titanium monoxide spectra are measured in the wavelength range of 500 nm to 750 nm, and molecular signatures include bands of the C 3 ∆ → X 3 ∆ α, B 3 Π → X 3 ∆ γ , and A 3 Φ → X 3 ∆ γ transitions. The spatially and temporally averaged spectra appear to be in qualitative agreement with previous temporally resolved studies that employed shorter wavelengths and shorter pulse durations than utilized in this work. The background signals in the current study are possibly due to particulate content in the plume. A chemical kinetic model of the plume is being developed that will be coupled to a diatomic emission model in order to extract a molecular temperature from the observed spectra.

Temporal evolution study of the plasma induced by CO2 pulsed laser on targets of titanium oxides

Spectrochimica Acta Part B: Atomic Spectroscopy, 2013

Laser induced breakdown spectroscopy Time-resolved optical emission spectroscopy High-power IR CO 2 pulsed laser Time of flight measurement Titanium oxides This paper reports studies on time-resolved laser induced breakdown spectroscopy (LIBS) of plasmas induced by IR nanosecond laser pulses on the titanium oxides TiO and TiO 2 (anatase). LIBS excitation was performed using a CO 2 laser. The laser-induced plasma was found strongly ionized yielding Ti + , O + , Ti 2+ , O 2+ , Ti 3+ , and Ti 4+ species and rich in neutral titanium and oxygen atoms. The temporal behavior of specific emission lines of Ti, Ti + , Ti 2+ and Ti 3+ was characterized. The results show a faster decay of Ti 3+ and Ti 2+ ionic species than that of Ti + and neutral Ti atoms. Spectroscopic diagnostics were used to determine the time-resolved electron density and excitation temperatures. Laser irradiation of TiO 2 -anatase induces on the surface sample the polymorphic transformation to TiO 2 -rutile. The dependence on fluence and number of irradiation pulses of this transformation was studied by micro-Raman spectroscopy.

Study of the plasma produced from laser ablation of a LBO crystal

Applied Surface Science, 2004

Optical emission spectra of the plasma produced by 1.06 mm Nd:YAG laser irradiation of a potassium titanium phosphate (KTP) crystal in vacuum and in air were recorded and analyzed in a spatially resolved manner. Electron temperatures and densities in the plasma in vacuum were determined with the Boltzmann plot method using five Ti(II) emission lines and the Stark-broadened linewidths of neutral K atoms, respectively. The dependence of the electron densities and temperatures on distance from the target surface and on laser irradiance were manifested. In order to see the effect of backing gas, we also performed laser ablation of a KTP crystal in air and compared the results with that of the ablation in vacuum. Gas dynamical parameters of the laser-induced KTP evaporation wave were simulated using a hydrocode developed in our group based on the self-similar solutions of the gas dynamical equations. Moreover, the velocity of the evaporating wave and the vapor pressure were calculated under different laser power densities. #

Laser Interaction with Tio 2 Nano Material Surface and Plasma Measurements

In this paper the plasma generated from the surface etching of (TiO2) surface in nano size, is studied and the surface morphology produced by this process. Since most of the deposited thin films are use the radicals, then these radicals are generated from the absorption of the electromagnetic radiation (laser) in our work are captured using very developed equipments. The generated plasma dramatically should be very dense and differ from those generated in the same way from the raw materials. Keywords-TiO2 nano disk, titanium dioxide surface etching, nano plasma properties, plasma generation in nano scale.

Ion and photon emission from laser-generated titanium-plasma

Applied Surface Science, 2008

Titanium-plasma was obtained by nanosecond pulsed laser ablation technique. A Nd:Yag laser was employed to irradiate titanium in vacuum. The ion emission from plasma was on-line monitored by an electrostatic ion energy analyzer which permitted to measure the ion kinetic energy and charge state. The visible photon emission was monitored by an optical spectrometer. The ion energy, charge state and angular distributions, the temperature and density of the non-equilibrium plasma were investigated. The temperature gradient of the plasma plume was evaluated and discussed. #

Ultra-fast laser ablation and deposition of TiO2

Applied Physics A, 2010

In this work we report on the properties of the ablation plume and the characteristics of the films produced by ultra-fast pulsed laser deposition (PLD) of TiO 2 in vacuum. Ablation was induced by using pulses with a duration of ≈300 fs at 527 nm. We discuss both the composition and the expansion dynamics of the TiO 2 plasma plume, measured by exploiting time-and space-resolved emission spectroscopy and gated imaging. The properties of the TiO 2 nanoparticles and nanoparticle-assembled films were characterized using different techniques, i.e. environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). It is suggested that most of the material decomposes in the form of nanoparticles.

SPECTROSCOPIC STUDY OF (TiO2)1-x(CuO)x PLASMA GENERATED BY Nd:YAG LASER

ARPN Journal of Engineering and Applied Sciences, 2018

Laser-induced (TiO 2) 1-x (CuO) x plasma, which is produced by laser. A pulse of Nd:YAG laser is supplied for duration 10 ns produce plasma from a planar (TiO 2) 1-x (CuO) x sample placed in a vacuum having a pressure of 10-3 mbar. The temperature of the plasma electrons is calculate by the Boltzmann plot methodology from of Ti and Cu emission lines of singly ionized, and the density of the plasma electron is calculated with the use of Stark broadened profiles. As well as the electron temprature is calculated within the values of (0.699-0.781) eV, and the density of electron is measured in the values of (34.7×10 18 – 50.5×10 18) cm-3 .

Spectroscopic and Morphological Study of Laser ablated Titanium

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. Abstract—The laser-induced breakdown spectroscopy (LIBS) and surface morphology of Titanium (Ti) plasma as a function of laser irradiance have been investigated under ambient environment of argon at fixed pressure of 50 Torr. Ablation was performed by employing Q-switched Nd:YAG laser pulses (λ ≈ 1064 nm, τ ≈ 10 ns, repetition rate ≈ 10 Hz). Ti targets were exposed to various laser intensities ranging from 6 to 50 GW/cm 2. LIBS analysis has been employed for the investigation of plasma parameters. Scanning Electron Microscope (SEM) analysis was employed for investigation of surface morphology. Ablation depth was measured by optical microscopy technique. It was observed that both plasma parameters, i.e., excitation temperature and electron density have been significantly influenced by laser irradiance. It is observed that with increasing laser irradiance up to 13 GW/cm 2 , the electron temperature decreases whereas number density significantly increases and attains its maxima. Afterwards by increasing irradiance electron temperature increases, attains its maxima and a decrease in electron number density is observed at irradiance of 19 GW/cm 2. Further increase in irradiance causes saturation with insignificant changes in both electron temperature and electron number density. This saturation in both excitation temperature and electron number density is explainable on the basis of self-sustaining regime. SEM micrographs reveal the ripple and cone-formation at the boundaries of ablated region of Ti. The height of cones as well as the ablation depth is maximum at irradiance of 13 GW/cm 2 whereas electron number density is also maximum. The maximum electron number density is considered to be responsible for maximum ablation as well as mass removal. A strong correlation between plasma parameters and surface morphology is established.