Physicalscience

1. DHANALAKSHMI SRINIVASAN
ENGINEERING COLLEGE
Name : C Padma Priya
Register num : 81042205108
Subject : Engineering Physics
Subject code : U20PH201
Dept & sec : B.Tech IT & B
Topics : Pulsed Laser deposition &
Electro deposition

2. PULSED LASER DEPOSITION
■ Pulsed Laser Deposition (PLD) is a thin film deposition
technique that uses a high-energy laser to ablate
material from a target and deposit it onto a substrate. It
is widely used in materials science and thin film
research to create high-quality thin films with precise
control over composition and structure

3. ■ The process of PLD involves several steps:
■ Target preparation: The material to be deposited, known as the
target, is prepared in the form of a solid pellet or a pressed powder.
The target should have a uniform composition and be free from
impurities.
■ Chamber setup: The PLD chamber is evacuated to create a low-
pressure environment to prevent contamination. The substrate onto
which the film will be deposited is mounted in the chamber, and the
target is positioned opposite to it.
■ Laser ablation: A high-energy laser, typically a pulsed laser, is focused
onto the target surface. The laser pulse vaporizes or ablates the
material from the target, creating a plasma plume or a cloud of
energetic species.

4. ■ Film deposition: The ablated material in the form of plasma plume
expands and travels across the vacuum chamber, eventually reaching
the substrate. The energetic species in the plasma condense and
deposit onto the substrate, forming a thin film. The substrate is
usually heated to promote adhesion and control the growth of the
film.
■ Film characterization: After the deposition, the thin film can be
characterized using various techniques to assess its properties, such
as thickness, composition, crystallinity, and surface morphology

6. •PLD offers several advantages over other thin film deposition
techniques. It allows the deposition of a wide range of materials,
including oxides, nitrides, metals, and complex compounds. The films
produced by PLD are often high quality, with excellent crystallinity and
low defect density. PLD also provides good control over the
stoichiometry and composition of the deposited films
•However, PLD also has some limitations. The deposition rate is
relatively low compared to other techniques like sputtering or chemical
vapor deposition. It is also challenging to scale up PLD for large-area
film deposition. Additionally, the process can introduce thermal and
mechanical stress into the deposited films, which may affect their
properties
•Overall, Pulsed Laser Deposition is a powerful technique for creating
thin films with precise control over composition, structure, and
properties. It continues to be an important tool in materials research
and development.

7. ELECTRO DEPOSITION
■ Electrodeposition, also known as electroplating or
electrolytic deposition, is a process of depositing a metallic
coating onto a substrate using an electrolytic cell. It involves
the use of an electric current to drive a redox reaction,
resulting in the deposition of a metal onto an electrode

8. The process of electrodeposition typically involves the following
steps:
1. Electrolyte preparation: An electrolyte solution is prepared by
dissolving a metal salt in a suitable solvent. The choice of
electrolyte depends on the metal to be deposited. For example, if
copper is to be deposited, a copper sulfate solution may be used.
2. Electrolytic cell setup: The electrolyte solution is placed in a
container, which serves as the electrolytic cell. Two electrodes are
immersed in the electrolyte: the anode and the cathode.
3. Electrolysis: An external power supply is connected to the anode
and cathode, creating a circuit. When the power supply is turned
on, a direct current (DC) passes through the cell. The anode is
connected to the positive terminal of the power supply, and the
cathode is connected to the negative terminal.

9. .4. Redox reactions: As the electric current flows through the
electrolyte, metal cations from the electrolyte are attracted to the
cathode (substrate). At the cathode, reduction occurs, and the
metal cations are reduced to metallic atoms or ions, which then
deposit onto the substrate, forming a metallic coating. At the
anode, oxidation occurs, releasing metal cations into the electrolyte
to replenish the metal ions being deposited.
5. Control of deposition parameters: The deposition process can be
controlled by adjusting various parameters, such as the current
density, deposition time, temperature, and electrolyte composition.
These parameters influence the thickness, adhesion, and quality of
the deposited metal coating.

11. Electrodeposition has numerous applications in various industries.
It is commonly used for decorative purposes, such as gold or silver
plating of jewelry, as well as for corrosion protection of metals.
Electroplating is also employed in electronic industries for
depositing conductive metal layers on circuit boards or connectors.
Additionally, electrodeposition plays a vital role in the fabrication of
microelectromechanical systems (MEMS), fuel cells, batteries, and
other electrochemical devices.
Advantage of electrodeposition is that it allows for precise control
over the thickness and uniformity of the deposited metal coating. It
also enables the deposition of complex shapes and can be applied
to a wide range of substrate materials. However, the process may
require careful consideration of factors like surface preparation,
bath composition, and current distribution to achieve desired
results.