Light and Matter Id / Licht und Materie Id : Infrared and Raman Spectra of Non-Metals

R. K. Wehner

ISBN 10: 3642464351 / ISBN 13: 9783642464355

Published by Springer, 2012

About this Item

Druck auf Anfrage Neuware - Printed after ordering - The dynamical properties of solids have recently attracted renewed interest in connection with the increasing understanding of phase transitions and re lated phenomena. In particular, soft modes or, more generally, phonon 'anom alies' seem to play an important role in structural and electronic phase tran sitions, such as ferroelectric or superconducting transitions. The understanding of the mechanisms responsible for the occurrence of unusually low frequencies in phonon spectra requires a detailed analysis of the microscopic forces governing the lattice vibrations. Of particular importance is the influence of the electron lattice interaction in the adiabatic approximation which in many cases is the origin of peculiarities in the phonon self-energy. In this work the vibrational spectra of pure non-metals and of those con taining point defects are investigated. ' In these materials the interrelation be tween the pseudo-harmonic forces (determining the phonon dispersion re lations) and the non-linear anharmonic and electron-phonon forces (as they act in infrared and Raman spectra) is most obvious and can be quantitatively analysed in terms of appropriate models. The main task is to arrive at a physically correct treatment of electronic degrees of freedom, as for example in an electronic 'shell' model, which leads to the description of phonon spectra in terms of long-range polarizabilities and short-range deformabilities. The pur pose of our review is to stimulate further investigations which, we hope, will result in explicit relations between the parameters of the semi-microscopic models and the matrix elements from the electronic band structure.

Seller Inventory # 9783642464355

Bibliographic Details

• Title: Light and Matter Id / Licht und Materie Id : Infrared and Raman Spectra of Non-Metals
• Publisher: Springer
• Publication Date: 2012
• Language: English
• ISBN 10: 3642464351
• ISBN 13: 9783642464355
• Binding: Taschenbuch
• Condition: Neu
• Dimensions: 244W x 170H x 34D millimeters 244 millimeters width by 170 millimeters height by 34 millimeters depth
• Weight: 1054 grams

About this title

Synopsis

The dynamical properties of solids have recently attracted renewed interest in connection with the increasing understanding of phase transitions and re­ lated phenomena. In particular, soft modes or, more generally, phonon 'anom­ alies' seem to play an important role in structural and electronic phase tran­ sitions, such as ferroelectric or superconducting transitions. The understanding of the mechanisms responsible for the occurrence of unusually low frequencies in phonon spectra requires a detailed analysis of the microscopic forces governing the lattice vibrations. Of particular importance is the influence of the electron­ lattice interaction in the adiabatic approximation which in many cases is the origin of peculiarities in the phonon self-energy. In this work the vibrational spectra of pure non-metals and of those con­ taining point defects are investigated. ' In these materials the interrelation be­ tween the pseudo-harmonic forces (determining the phonon dispersion re­ lations) and the non-linear anharmonic and electron-phonon forces (as they act in infrared and Raman spectra) is most obvious and can be quantitatively analysed in terms of appropriate models. The main task is to arrive at a physically correct treatment of electronic degrees of freedom, as for example in an electronic 'shell' model, which leads to the description of phonon spectra in terms of long-range polarizabilities and short-range deformabilities. The pur­ pose of our review is to stimulate further investigations which, we hope, will result in explicit relations between the parameters of the semi-microscopic models and the matrix elements from the electronic band structure.