LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS)

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PRESENTATION

Presenters KAMRAN ALI
UZAIR NIAZ Roll No.s
19702, 19731
Topic Of Presentation LASER INDUCED
BREAKDOWN SPECTROSCOPY (LIBS)
Course
NANOTECHNOLOGY
Study Level
BACHELOR STUDIES



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• LASER-INDUCED BREAKDOWNSPECTROSCOPY
• (LIBS)
•  
• LIBS stands for Laser-Induced Breakdown
  Spectroscopy, which is an
• analytical technique used for elemental
  analysis of materials. It involves
• the use of a laser to generate a plasma on
  the surface of a sample, and
• the emission spectrum of the plasma is
  then analyzed to determine the
• elemental composition of the sample.
• LIBS is easily performed by focusing a highly
  energetic
•   laser pulse onto the surface of a
  solid or liquid, or into
• sample volume of a liquid, gas, or
  cloud of solid or liquid
• particles in gas (aerosol).
• The resulting microplasma contains excited
  molecular and
• atomic species from the bulk sample, as
  well as ablated particulates.

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• These excited-state species emit light at unique
  wavelengths.
• This light can then be collected with a
  spectrometer and parsed
• to a computer.
• Since each element has a unique emission
  spectrum,
• all elements can be detected with LIBS. LIBS
  requires little or no
• sample preparation and can be performed
  remotely and in real time.

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• The Construction Of A LIBS
• The construction of a LIBS system typically
  involves the following components
• LASER
• OPTICS
• SAMPLE CHAMBER
• SPECTROMETER
• DETECTOR
• DATA ACQUISITION SYSTEM
• CALIBRATION STANDARDS
• DATA ANALYSIS SOFTWARE
  
• It's important to note that the construction
  of a LIBS system can vary depending on the
  specific application and the desired performance
  characteristics. Advanced LIBS systems may
  include additional features such as multiple
  lasers for different excitation wavelengths,
  advanced spectrometers with high-resolution
  capabilities, and automated sample handling
  systems.

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• HOW DOES LIBS WORK?
• Laser Pulse A high-energy laser pulse,
  typically in the ultraviolet, visible, or
  near-infrared
• range, is focused onto the surface of the
  sample.
• The laser pulse vaporizes and ablates a small
  amount of material from the surface, creating a
• plasma plume.
• When the short-pulse laser beam is focused
• onto the sample surface, a small volume of
• the sample mass is ablated (i.e. removed
• via both thermal and non-thermal mechanisms)
  
• in a process known as Laser Ablation.
• The laser energy causes the ablated material to
• rapidly expand and ionize, forming a

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• When the laser pulse terminates, the plasma
  starts to cool.
• During the plasma cooling process,
• the electrons of the atoms and ions at the
  excited electronic
• states fall down into natural ground states,
  causing the
• Plasma to emit light with discrete spectral
  peaks.
• A spectrometer or other light collection
  system is used to

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• The collected spectrum is compared to a
• pre-existing spectral database or a
  calibration
• curve to determine the elemental
  composition
• of the sample.
• Each element in the periodic table is
  associated
• with unique LIBS spectral peaks.
• By identifying different peaks for the
• analyzed samples, its chemical composition
• can be rapidly determined.
• Often, information on LIBS peak intensities
• can be used to quantify the concentration
• of trace and major elements in the sample.
• With the advancement of powerful chemometric
  software for LIBS data analysis, and with
• steady progress in understanding laser
  ablation fundamentals, todays analytical

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Advantages Of
LIBS

• LIBS is a versatile multi-elemental technique
  having many benefits. Some of the advantages are
  described as
• Little or no sample preparation is required
  foe elemental assay .
• The minute volume of the sample is vaporized
  (usually between 0.1 µg
• and 0.1 mg) generally considered as quasi
  non-destructive method.
• It has the ability to examine very hard
  materials, such as ceramics,
• glasses and superconductors, which are
  complicated and difficult to
• process, digest and dissolve.
• It has ability for direct aerosol detection
  or ambient air.

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Limitations Of LIBS

• There are some limitations which effect the
  performance of this technique. Some of the
  drawbacks of this spectroscopic technique are
  described below
• The arrangement Of the system is expensive and
  highly complicated.
• Suitable criteria is difficult to achieve due
  to which it is known as semi-
• quantitative method.
• Low precision, generally 5 to 10 percent due
  to the sample
• homogeneity, sample matrix, and the laser
  excitation properties.
• The risk of optical damage due to laser beams
  of high intensity.

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Thank You