Lattice Parameter Calculation
A very precise knowledge of the lattice parameter(s) of materials is
important in solid-state investigations.
(1) In developing satisfactory concepts of bonding energies in
(2) Precise lattice parameter me
The intensities of diffracted beams
The positions of the atoms in the unit cell affect the intensities but
not the directions of the diffracted beams.
(a) Base-centered and (b) body-centered orthorhombic unit cells
Diffraction from the (001)
X-ray intensity of continuous spectrum
Intensity of K characteristic spectrum
I K line Bi (V VK )
Mosleys law wavelength of any particular line
decreased as the atomic number of the emitter
C (Z )
K1 = 0.709
Essential condition for diffraction
n 2d sin
Two geometrical facts are worth remembering:
(1) The incident beam, the normal to the reflecting plane, and the
diffracted beam are always coplanar.
(2) The angle between the diffracted b
Nature of X-rays
The boundaries between
regions are arbitrary, since
no sharp upper or lower
limits can be assigned.
1 kX= 1.00202A
Can pass human body, wood, quite thick pieces
Diffraction under non-ideal conditions:
Incident beam composed of;
Perfectly parallel rays
Strictly monochromatic radiation
Destructive interference produced in all directions except those
of the diffra
X-Ray Diffraction (XRD)
Few relationships for crystals
Indices for Directions and Planes in Cubic crystals
Planes of a zone are planes which are all parallel to one line,
called the zone axis, and the zone, i.e., the set of planes, is
Production of X-ray
X-rays are produced whenever high-speed electrons collide with
a metal target.
Any x-ray tube must therefore contain
(a) a source of electrons,
(b) a high accelerating voltage, and
(c) a metal target.
(d) Furthermore, since most of the