X-Ray Diffraction | Crystal Structure | Why is XRD Important?

Why is XRD Important?

It’s useful for studying Crystal structure

This method have the details about

  • Grain size (or) Crystal size
  • Orientation of the crystal
  • Cold worked, Distorted and Internally stressed crystals
  • Re-Crystallization
  • Preferred orientation etc

Methods of Examining and Measuring the condition of Crystal Structure

  1. The Laue back reflection method
  2. The Rotating Crystal method
  3. The DeBye- Scherrer (or) Powder method:

The Laue back Reflection method:

It’s applicable to single crystals (or) poly-Crystalline masses.

When a beam of Mono chromatic (i.e. of Single Wavelength) X-Ray is directed as a narrow pencil at a specimen of a metal diffraction takes place at certain of the crystallographic planes.

03-laue method- x-rays sheild

01-laue back reflection- method-X-ray-diffraction

01-electron-waves-travel-x-rays03-LaueBack reflection

02-laue-BACK-method

The Rotating Crystal method:

It’s a useful method for determining angles and positions of planes.

Crystallographic planes are brought in to reflecting positions by rotating a crystal (Specimen) about one of it’s axis while simultaneously radially it with a beam of mono chromatic x-Rays.

If crystal orientation planes are known, the angles and directions can be calculated.

04-rotating-crytal-method-x-ray-diffration-crystal-structure

05-diffractometer-x ray detector-rotation crystal

The DeBye- Scherrer (or) Powder method:

The narrow pencil of monochromatic X-Rays is diffracted from the powder and recorded by the photographic film as a series of lines of varying armature.

By the Bragg Equation:

nλ=2d Sinθ

Where,

λ– Wave length of X-ray

d- Spacing of the atomic planes

θ – Angle of reflection

06-debye-scherrer-powder-method

07-debye-scherrer-powder-method

 

 

 

 

[jetpack_subscription_form show_only_email_and_button=”true” custom_background_button_color=”#ff6900″ custom_text_button_color=”#0693e3″ submit_button_text=”Subscribe” submit_button_classes=”wp-block-button__link has-text-color has-vivid-cyan-blue-color has-background has-luminous-vivid-orange-background-button-color” show_subscribers_total=”false” ]
  • Dyson Electric Car | Solid-State Lithium Ion Battery | Dyson Digital Hyperdymium motor
    Dyson Electric Car Concept Main Innovations The key developments of Dyson Electric cars are their batteries and its digital Hyperdymium brushless motors. Such techs are described in depth in the following articles. 1) Solid-state lithium ion battery Throughout usage of lithium-ion technology a thin film of non-inflammable material replaced the pressurized liquid electrolyte, work as […]
  • Dyson Sakti3 | Dyson Solid State Battery | Dyson Electric Car Battery
    Dyson Sakti3 Solid State Li-ion Battery The code nicknamed “N526” had a reported driving range of approximately 965 km on single charge utilizing Dysons patented solid-state battery technology. For contrast, Tesla, the American leader for powertrain cars, can travel up to 580 km with a single charge in a 7-seater Model X Long Range. Dyson […]
  • Solid State Battery | Solid State Electrolyte | Thin Film Batteries
    Solid state battery You should definitely have a lithium-ion battery in your phone or camera that is compact, charges faster and rechargeable. These are solid lithium electrodes mounted in a liquid electrolyte. Solid state batteries dampen liquid electrolyte,  with a rigid conducting substance for example polymer or ceramics. These batteries would charge faster and last […]
  • Dyson Car Patent | Dyson EV Patent
    “All done, see you! Internal combustion engines, cherish electric vehicles” – This is the of mantra of automobile makers, all of whom commit to switch towards emission-free vehicles, whereas the policymakers have tossed forth several proposals in the span of three decades to ban gasoline and diesel engines. Thank goodness, Dyson has approached to agonistically […]
  • Transportation and Climate Change | Carbon Emissions by Transport Type
    Transportation and Climate Change Road transport produces about one fifth of the world’s CO2, the main green house gas (GHG) emissions. Even though the emissions decreased by 3.3% in 2012, they are 20.5% higher than the 1990 emissions. Transport is the world’s main sector in which emissions of GHGs continue to increase. Growing nation should […]

Introduction | Structure of Metals and Alloys | Crystalline materials

INTRODUCTION TO STRUCTURE OF METALS AND ALLOYS

Crystalline Materials:

  • A crystalline material is one in which the atoms are situated in a repeating (or) periodic array over large atomic distances.

01-space-lattice-unit-cell-represenatation

 

Non Crystalline Materials:

  • Materials that do not crystallize are called non-crystalline (or) Amorphous materials

Space Lattice:

  • Lattice is the regular geometrical arrangement of points in crystal space.

01-lattice-crystal structure

 

  • The atoms arrange themselves in distinct pattern in space is called a Space Lattice.
  • Atoms in crystalline materials are arranged in a regular 3 – Dimensional repeating pattern known as Lattice Structure.
  • They are divided by network of lines in to equal volumes, the points of intersection are known as Lattice Points.

Unit Cell:

01-unit cell

  • It is the smallest portion of the lattice which repeated in all directions.
  • 3D visualization of 14 Space Lattices are known as Bravai’s Space Lattice.
  • If a unit cell contains lattice points only at it’s corners, then it is called Primitive Unit Cell (or) Simple Unit Cell.
  • Three edge length x,y, & z and three interaxial angles α, β, & γ are termed as Lattice Parameters.

Crystal System:

  • It is a scheme by which crystal structures are classified according to unit cell geometry.

Types of Crystal Systems:

  • Cubic
  • Tetragonal
  • Hexagonal
  • Orthorhombic
  • Rhombohedral
  • Monoclinic
  • Triclinic

Crystal Systems

image

Simple Crystal Structure:

Body Centered Cubic Structure (BCC)

  • Unit cell contains 2 atoms
  • Lattice Constant a= 4r / √3, where r is atomic radius
  • Atomic packing factor APF = 0.68
  • Metals are Vanadium, Molybdenum, Titanium, Tungsten

0I-bcc-structure-body center cubic02-bcc-structure-body center cubic

03-bcc-structure-body center cubic

 

Face Centered Cubic (FCC)

  • Unit cell contains 4 atoms
  • Lattice Constant a= 4r / √2, where r is atomic radius
  • Atomic packing factor APF = 0.72
  • FCC structures can be plastic deformed at severe rates
  • Metals are Copper, Aluminum, Phosphorous, Nickel, Cobalt etc

02-fcc-structure-face center cubic-unit cell

0I-fcc-structure-face center cubic-unit cellHexagonal Closed Packed Structure (HCP)

  • Unit cell contains 3 atoms
  • Axial ratio c/a, where ‘c’ is Distance between base planes, ‘a’ is Width of Hexagon
  • Axial Ratio varies from 1.58 for Beryllium to 1.88 for Cadmium (Therefore  a=2.9787, c=5.617)
  • Atomic packing factor APF = 0.74
  • Metals are Zinc, Cadmium, Beryllium, Magnesium etc

0I-hcp-structure-Hexagonal close packed-unit cell

0I-hcp-structure-hexagonal close packed

0I-hcp ball-structure-Hexagonal close packed-unit cell

 

 

Crystallographic Planes and Directions

The Layers of atoms in the planes along which atoms are arranged is known as “Atomic” (or) “Crystallographic planes”.

Miller Indices:

Miller Indices is a system of notation that denotes the orientation of the faces of a crystal and the planes and directions of atoms within that crystal.

Miller Indices for Planes:

1. The (110) surface

02-miller indices-crystalographic planes

 

Intercepts :   a , a , ∞

Fractional intercepts :   1 , 1 , ∞

Miller Indices :   (110)

 

2. The (111) surface

03-miller indices-crystalographic planes

 

Intercepts :   a , a , a

Fractional intercepts :   1 , 1 , 1

Miller Indices :   (111)

The (100), (110) and (111) surfaces considered above are the so-called low index surfaces of a cubic crystal system.

 

3. The (210) surface

04-miller indices-crystalographic planes

 

Intercepts :   ½ a , a , ∞

Fractional intercepts :   ½ , 1 , ∞

Miller Indices :   (210)

 

 

 

[jetpack_subscription_form show_only_email_and_button=”true” custom_background_button_color=”#ff6900″ custom_text_button_color=”#0693e3″ submit_button_text=”Subscribe” submit_button_classes=”wp-block-button__link has-text-color has-vivid-cyan-blue-color has-background has-luminous-vivid-orange-background-button-color” show_subscribers_total=”false” ]
  • Dyson Electric Car | Solid-State Lithium Ion Battery | Dyson Digital Hyperdymium motor
    Dyson Electric Car Concept Main Innovations The key developments of Dyson Electric cars are their batteries and its digital Hyperdymium brushless motors. Such techs are described in depth in the following articles. 1) Solid-state lithium ion battery Throughout usage of lithium-ion technology a thin film of non-inflammable material replaced the pressurized liquid electrolyte, work as […]
  • Dyson Sakti3 | Dyson Solid State Battery | Dyson Electric Car Battery
    Dyson Sakti3 Solid State Li-ion Battery The code nicknamed “N526” had a reported driving range of approximately 965 km on single charge utilizing Dysons patented solid-state battery technology. For contrast, Tesla, the American leader for powertrain cars, can travel up to 580 km with a single charge in a 7-seater Model X Long Range. Dyson […]
  • Solid State Battery | Solid State Electrolyte | Thin Film Batteries
    Solid state battery You should definitely have a lithium-ion battery in your phone or camera that is compact, charges faster and rechargeable. These are solid lithium electrodes mounted in a liquid electrolyte. Solid state batteries dampen liquid electrolyte,  with a rigid conducting substance for example polymer or ceramics. These batteries would charge faster and last […]
  • Dyson Car Patent | Dyson EV Patent
    “All done, see you! Internal combustion engines, cherish electric vehicles” – This is the of mantra of automobile makers, all of whom commit to switch towards emission-free vehicles, whereas the policymakers have tossed forth several proposals in the span of three decades to ban gasoline and diesel engines. Thank goodness, Dyson has approached to agonistically […]
  • Transportation and Climate Change | Carbon Emissions by Transport Type
    Transportation and Climate Change Road transport produces about one fifth of the world’s CO2, the main green house gas (GHG) emissions. Even though the emissions decreased by 3.3% in 2012, they are 20.5% higher than the 1990 emissions. Transport is the world’s main sector in which emissions of GHGs continue to increase. Growing nation should […]