Seminars

Crystallography and Diffraction

How atoms are ordered in the lattice?

It is studied by Crystallography

How atoms are ordered in the lattice?

It is studied by Crystallography

All information needed is included in the

International Tables for Crystallography

How atoms are ordered in the lattice?

It is studied by Crystallography

Each particular structure can be

described using a given Space Group

All information needed is included in the

International Tables for Crystallography

How atoms are ordered in the lattice?

It is studied by Crystallography

Each particular structure can be

described using a given Space Group

All information needed is included in the

International Tables for Crystallography

To learn more about Space Groups, see the following Seminars:

Space Group Overview

Space Group Symbol

Getting the Table of Equivalent Positions

Atoms in 3D-lattices form planes …

Atoms in 3D-lattices form planes …

- Vertical

Atoms in 3D-lattices form planes …

- Vertical - Horizontal

Atoms in 3D-lattices form planes …

- Vertical - Horizontal

- and in many other directions …

Can we calculate the spacing between planes?

spacing

Atoms in 3D-lattices form planes …

- Vertical - Horizontal

- and in many other directions …

Can we calculate the spacing between planes?

spacing

Yes, we can.

Atoms in 3D-lattices form planes …

- Vertical - Horizontal

- and in many other directions …

Can we calculate the spacing between planes?

spacing

Yes, we can.

For orthogonal systems (square

angles, 90°) it is quite easy.

Atoms in 3D-lattices form planes …

- Vertical - Horizontal

- and in many other directions …

Can we calculate the spacing between planes?

spacing

Yes, we can.

For orthogonal systems (square

angles, 90°) it is quite easy.

To learn about it, see the seminar:

Spacing in Orthogonal Systems

Atoms in 3D-lattices form planes …

- Vertical - Horizontal

- and in many other directions …

Throwing a

X-ray beam on

Throwing a

X-ray beam on

… and using

a detector …Detector

Throwing a

X-ray beam on

… and using

a detector …

Inte

nsi

ty

Position of the detector

… one gets a signal so-called diffractogramDetector B

Throwing a

X-ray beam on

… and using

a detector …

Inte

nsi

ty

Position of the detector

… one gets a signal so-called diffractogramDetector B

Each peak is assigned to a plane of the lattice

Throwing a

X-ray beam on

… and using

a detector …

Inte

nsi

ty

Position of the detector

… one gets a signal so-called diffractogramDetector B

Each peak is assigned to a plane of the lattice

If we know the position of the peak,

we can calculate the spacing between planes

Throwing a

X-ray beam on

… and using

a detector …

Inte

nsi

ty

Position of the detector

… one gets a signal so-called diffractogramDetector B

Each peak is assigned to a plane of the lattice

If we know the position of the peak,

we can calculate the spacing between planes

To learn about it, see the seminar:

Bragg Equation

Throwing a

X-ray beam on

Inte

nsi

ty

Position of the detector

Detector B

If we know the spacing of all planes,

then we can get the index of the planes,

as well as the centering of the unit cell.

… and using

a detector …… one gets a signal so-called diffractogram

Inte

nsi

ty

Position of the detector

Detector B

If we know the spacing of all planes,

then we can get the index of the planes,

as well as the centering of the unit cell.

It is easy to do it in the cubic system. To learn about it, see the seminar:

Indexing in the Cubic System

… and using

a detector …… one gets a signal so-called diffractogram

Inte

nsi

ty

Position of the detector

Detector B

Finally, if we know the width of the peaks,

we can calculate the particle size,

and an average of the defects in the lattice

… and using

a detector …… one gets a signal so-called diffractogram

Inte

nsi

ty

Position of the detector

Detector B

Finally, if we know the width of the peaks,

we can calculate the particle size,

and an average of the defects in the lattice

Scherrer Equation

It is easy to calculate the particle size. To learn how, see the seminar:

Williamson-Hall Equation

… and using

a detector …… one gets a signal so-called diffractogram

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