Download (4Mb) - Etheses - Saurashtra University

Chapter III CHN Analysis, FT IR …..
There are three types of powder methods, differentiated by the relative
position of the specimen and the film.
Debye-Scherrer Method:
The film is placed on the surface of a cylinder and specimen on the axis of the
cylinder.
Focusing Method:
The film, specimen and X-ray source are all placed on the surface of a
cylinder.
Pinhole Method:
The film is flat, perpendicular to the incident X-ray beam and located at any
convenient distance from the specimen.
For the purpose of simultaneous and quick measurement of the
positions and intensities of diffraction lines the diffracto-meters are
advantageous; on the other hand, the diffraction cameras are preferred when
a very small amount of specimen is available, if an entire diffraction ring is
required to be recorded in order to do the rapid estimation of grain size and
preferred orientation and in case of large immovable specimen. The powder
photographic methods are well described by Klug and Alexander [27] as well
as Azaroff and Buerger [25]. The simplest and most inexpensive way of
practicing the powder method is to record the X-ray diffraction on
photographic film, using a powder camera. A more elaborate way is to detect
the diffracted radiation by means of a quantum counter, like Geiger counter.
The use of counter diffracto-meter and recorder equipment is justified chiefly
when one wants to examine different samples rapidly. Such methods also
have a real advantage whenever accurately measured intensities are
147