Scanning Electron Microscope and X-ray diffraction.?

Question

I would like some help on:
how else two things work?.
what are they used for?
how did they come into being?
what are the advantages and disadvantages?
and any other details.
thanks in advance

Answer 1

Electron diffraction is a technique used to study matter by firing electrons at a sample and observing the resulting interference pattern. This phenomenon occurs due to the wave-particle duality, which states that a particle of matter (in this case the incident electron) can be described as a wave. For this reason, an electron can be regarded as a wave much like sound or water waves. This technique is similar to X-ray diffraction and neutron diffraction.
Electron diffraction is most frequently used in solid state physics and chemistry to study the crystal structure of solids. These experiments are usually performed in a transmission electron microscope (TEM), or a scanning electron microscope (SEM) as electron backscatter diffraction. In these instruments, the electrons are accelerated by an electrostatic potential in order to gain the desired energy and wavelength before they interact with the sample to be studied.
The periodic structure of a crystalline solid acts as a diffraction grating, scattering the electrons in a predictable manner. Working back from the observed diffraction pattern, it may be possible to deduce the structure of the crystal producing the diffraction pattern. However, the technique is limited by the phase problem.
Apart from the study of crystals, electron diffraction is also a useful technique to study the short range order of amorphous solids, and the geometry of gaseous molecules.
The de Broglie hypothesis, formulated in 1926, predicts that particles should also behave as waves. De Broglie's formula was confirmed three years later for electrons (which have a rest-mass) with the observation of electron diffraction in two independent experiments. At the University of Aberdeen George Paget Thomson passed a beam of electrons through a thin metal film and observed the predicted interference patterns. At Bell Labs Clinton Joseph Davisson and Lester Halbert Germer guided their beam through a crystalline grid. Thomson and Davisson shared the Nobel Prize for Physics in 1937 for their work.

Answer 2

XRD usually involves crystalline characterization of a bulk material and TEM is of a specific site or location.