EXAFS: Basic Principles and Data Analysis by Boon K. Teo

By Boon K. Teo

The phenomenon of prolonged X-Ray Absorption superb constitution (EXAFS) has been recognized for a while and used to be first taken care of theoretically through Kronig within the Thirties. contemporary advancements, initiated by means of Sayers, Stern, and Lytle within the early Nineteen Seventies, have resulted in the popularity of the structural content material of this system. whilst, the supply of synchrotron radiation has tremendously more suitable either the purchase and the standard of the EXAFS facts over these available from traditional X-ray resources. Such advancements have verified EXAFS as a strong instrument for constitution reports. EXAFS has been effectively utilized to quite a lot of major clinical and technological platforms in lots of assorted fields comparable to inorganic chemistry, biochemistry, catalysis, fabric sciences, and so forth. this can be very valuable for structures the place single-crystal diffraction strategies usually are not easily appropriate (e.g., fuel, liquid, resolution, amorphous and polycrystalline solids, surfaces, polymer, etc.). although the EXAFS method and purposes have matured drastically during the last decade or so, no introductory textbook exists. EXAFS: easy rules and information research represents my modest try to fill this type of hole. during this e-book, I goal to introduce the subject material to the amateur and to aid alleviate the confusion in EXAFS information research, which, even supposing turning into progressively more regimen, remains to be a slightly tough recreation and will, now and then, discourage the beginners.

Show description

Read or Download EXAFS: Basic Principles and Data Analysis PDF

Best inorganic books

Handbook on the Physics and Chemistry of Rare Earths

This carrying on with authoritative sequence bargains with the chemistry, fabrics technological know-how, physics and expertise of the infrequent earth parts in an built-in demeanour. each one bankruptcy is a complete updated, serious overview of a selected phase of the sector. The paintings bargains the researcher and graduate pupil a whole and thorough insurance of this attention-grabbing box.

Inorganic Synthesis, Vol. 31

The volumes during this carrying on with sequence offer a compilation of present thoughts and ideas in inorganic artificial chemistry. comprises inorganic polymer syntheses and preperation of significant inorganic solidsd, sutheses utilized in the advance of pharamacologically energetic inorganic compounds, small-molecule coordination complexes, and similar compounds.

Hydrogen Materials Science and Chemistry of Carbon Nanomaterials: Proceedings of the NATO Advanced Research Workshop on Hydrogen Materials Science an Chemistry ... II: Mathematics, Physics and Chemistry)

The 2003 foreign convention "Hydrogen fabrics technology and Chemistry of Carbon Nanomaterials" was once held in September 2003. within the culture of the sooner ICHMS meetings, this assembly served as an interdisciplinary discussion board for the presentation and dialogue of the newest learn on transition to hydrogen-based power structures, applied sciences for hydrogen creation, garage, usage, fabrics, power and environmental difficulties.

A Tale of Seven Elements

In 1913, English physicist Henry Moseley validated a sublime procedure for "counting" the weather in line with atomic quantity, ranging them from hydrogen (#1) to uranium (#92). It quickly grew to become transparent, besides the fact that, that seven parts have been mysteriously lacking from the lineup--seven parts unknown to technological know-how.

Additional info for EXAFS: Basic Principles and Data Analysis

Sample text

Since the effective photon mass is negligible compared with that of the atom, the elastically scattered photon carries away all its initial energy, giving rise to no loss in energy (or change in wavelength). The Rayleigh scattering cross-section for atoms is proportional to the square of the atomic scattering factor integrated over all directions and hence is proportional to Z2. However, since the photoelectric absorption increases as Rayleigh scattering is in general less important than true absorption except at low photon energies and/or for light elements.

In order to determine Nand (1, F(k) must be known reasonable well; similarly, in order to determine r, q,(k) must be known accurately. In practice, F(k) and q,(k) can be determined empirically from model compounds of known structure (cf Chapter 6) or calculated theoretically (cf Chapter 7) from first principles. Structural determinations via EXAFS depend on the feasibility of resolving the data into individual waves corresponding to the different types of neighbors of the absorbing atom. This can be accomplished by either curve-fitting or Fourier transform techniques.

The theory and the use of multiple scattering formalism in bond angle determination will be discussed in Chapter 8. Finally, it should be emphasized that the phase shifts are unique only if the energy thresholds, Eo, are specified (cf Chapter 7). Changing Eo will change the momentum k and hence the phase shift function ยข(k). It is clear then that, in order to fit experimental data based upon some empirical Eo with theoretical phase shifts or phase shifts derived from some model compounds. we must allow Eo to vary.

Download PDF sample

Rated 4.53 of 5 – based on 4 votes