Describe the main operating principle of the X-Ray Diffraction
(XRD) technique for analyzing the internal structure of powders and
bulk solid samples. Use figures to illustrate your answer.
refrences needed
How
are the interactions between X-Ray Diffraction with bilogical
molecules such as proteins and DNA?
What patterns could you observe in a XRD?
How do you do XRD of DNA?
Could you identify mutations by doing an XRD of DNA?
A molecular is injected into the right basilic vein. It is
visible on x-ray in the bile and is used to visualize the biliary
system for diagnostic study. Trace the molecule from injection to
its exit from the body.
Explain:
a) The similarity between the electron and the X-ray diffraction
patterns of aluminium.
b) The line in the hydrogen atom spectrum splits into two when
placed in a magnetic field.
c) The appearance of coloured lines for H atom in the Balmer series
while the Lyman series can only be observed with an ultraviolet
lamp.
The first four peaks in the X-ray powder diffraction pattern of
sodalite are at 2 values of 9.97°, 14.12°, 17.32° and 20.02°. The
radiation used for the experiment was Cu K with = 1.5418 Å.
Determine the lattice type and calculate the length, a, of the
cubic unit-cell.
Assume that an X-ray diffraction pattern is taken from two
specimens of pure Ni. The two specimens are identical except that
one contains numerous twins, while the other is untwinned. Would
the XRD patterns show a larger number of diffraction peaks for the
specimen containing the twins? Explain the reasoning behind your
answer.
Describe the powder X-ray diffraction experiment. List the basic
components in your diagram and discuss the features/roles of each
component. Include Bragg’s Law as well as coherent and incoherent
scattering. What types of information can be obtained using this
technique? Pros and cons with respect to single crystal XRD?