Posted tagged ‘photographic film’

X RAY DIFFRACTION

August 23, 2011

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-lauemethod

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

X RAY DIFFRACTION

August 23, 2011

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-lauemethod

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