Engineering Assignment 代写 Powder X Ray Diffraction
X-ray radiography is used for creating images of light-opaque materials. It relies on the relationship between density of materials and absorption of x-rays. Applications include a variety of medical and industrial applications.
X-ray crystallography relies on the dual wave/particle nature of x-rays to discover information about the structure of crystalline materials.
X-ray fluorescence spectrometry relies on characteristic secondary radiation emitted by materials when excited by a high-energy x-ray source and is used primarily to determine amounts of particular elements in materials.
Strengths and Limitations of X-ray Powder Diffraction (XRD)
Strengths
Powerful and rapid (< 20 min) technique for identification of an unknown mineral
In most cases, it provides an unambiguous mineral determination
Minimal sample preparation is required
XRD units are widely available
Data interpretation is relatively straight forward
Limitations
Homogeneous and single phase material is best for identification of an unknown
Must have access to a standard reference file of inorganic compounds (d-spacing's, )
Requires tenths of a gram of material which must be ground into a powder
For mixed materials, detection limit is approximate 2% of sample.
For unit cell determinations, indexing of patterns for non-isometric crystal systems is complicated
Peak overlay may occur and worsens for high angle 'reflections'
Future Prospective:-
The method also revealed the structure and functioning of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystallography is still the chief method for characterizing the atomic structure of new materials and in discerning materials that appear similar by other experiments. X-ray crystal structures can also account for unusual electronic or elastic properties of a material, shed light on chemical interactions and processes, or serve as the basis for designing pharmaceuticals against diseases.
It's future is bright because in nano technology, Solid Oxygen ε-Phase Crystal Structure Determined only with the help of powder x ray diffraction. All companies attempted powder X-ray diffraction experiments and structural analyses for the ε-phase in nano technology. In future, this non-destructive technique widely applied for the characterization of crystalline materials.
Engineering Assignment 代写 Powder X Ray Diffraction
