L18 X-ray Diffraction from Solids

X-ray diffraction - what is required for diffraction to occur at the same angle in both waves

They need to be in phase

Bragg’s Law to find lattice cell paramaters using angle of diffraction

The important parameter we are looking for is d - the spacing between Miller planes in the crystal

How can data on the diffraction angle let you determine lattice parameters

The structure factor - a mathematical description of x-ray scattering

Calculating electron density

Two factors in the Fourier Transform relating to the unit cell and lattice

What is the phase problem

Systematic absences of diffraction peaks in crystals

Example calculation to determine systematic absences in BCC

Restrictions on hkl to see systematic absence

Packing efficiency calculation

Space filling - which stacking layouts lead to which types of holes

What is Shannon ionic radii and how is it found

Using electron density maps

What affects the peak intensities in x ray diffraction and why

Why do different mirror planes have different intensities

What are Cu X-ray source doublets

Generally not going to be seen

What governs x-ray diffraction peak width