Powder Diffraction - Spallation Neutron Source

Microstrain Broadening
When a material has residual
stresses present, some crystallites
are compressed. This must be
balanced by other crystallites that
are stretched (because ∑F=ma=0)
This leads to a range of lattice
constants.
The spread between diffraction
locations for the maximum and
minimum lattice constant
increases linearly with Q (∆Q/Q or
∆d/d = constant)
b*
a*