Electron-Phonon Interactions and Phase Transitions

✍ Scribed by J. Friedel (auth.), Tormod Riste (eds.)

• Publisher: Springer US
• Year: 1977
• Tongue: English
• Leaves: 430
• Series: NATO Advanced Study Institutes Series 29
• Edition: 1
• Category: Library

✦ Synopsis

This NATO Advanced Study Institute was the fourth in a series devoted to the subject of phase transitions and instabilities with particular attention to structural phase transforma~ions. Beginning wi th the first Geilo institute in 19'(1 we have seen the emphasis evolve from the simple quasiharmonic soft mode description within the Landau theory, through the unexpected spectral structure re­ presented by the "central peak" (1973), to such subjects as melting, turbulence and hydrodynamic instabilities (1975). Sophisticated theoretical techniques such as scaling laws and renormalization group theory developed over the same period have brought to this wide range of subjects a pleasing unity. These institutes have been instrumental in placing structural transformations clearly in the mainstream of statistical physics and critical phenomena. The present Geilo institute retains some of the counter cul­ tural flavour of the first one by insisting whenever possible upon peeking under the skirts of even the most successful phenomenology to catch a glimpse of the underlying microscopic processes. Of course the soft mode remains a useful concept, but the major em­ phasis of this institute is the microscopic cause of the mode softening. The discussions given here illustrate that for certain important classes of solids the cause lies in the electron phonon interaction. Three major types of structural transitions are considered. In the case of metals and semimetals, the electron phonon interaction relie6 heavily on the topology of the Fermi surface.

✦ Table of Contents

Front Matter....Pages i-xv
Phase Changes and Electron Phonon Couplings in Perfect Crystals. Modulated Structures. An Introduction....Pages 1-49
Neutron Scattering Studies of Electron-Phonon Interactions....Pages 50-65
Phase Transitions in Quasi One-Dimensional Metals (TTF-TCNQ and KCP)....Pages 66-87
Solitons and Charge Density Waves....Pages 88-106
Charge Density Waves in Layered Compounds....Pages 107-136
Landau Theory of Charge Density Waves....Pages 137-141
Microscopic Model of Charge Density Waves in 2H-TaSe 2 ....Pages 142-149
Light Scattering by Charge Density Wave Modes in KCP and 2H-TaSe 2 ....Pages 150-152
Symmetry Classification of Modulated Structures....Pages 153-171
Superspace Groups for the Classification of Modulated Crystals....Pages 172-180
Structural Phase Transitions and Superconductivity in A-15 Compounds....Pages 181-193
Superconductivity and Martensitic Transformations in A-15 Compounds....Pages 194-199
p-d Hybridization, Incipient Lattice Instabilities and Superconductivity in Transition Metal Compounds....Pages 200-208
Pseudo-Spin Approach to Structural Phase Transitions....Pages 209-244
Theory of Jahn-Teller Transitions....Pages 245-270
Local Jahn-Teller Effect at a Structural Phase Transition....Pages 271-276
Optical Studies of Jahn-Teller Transitions....Pages 277-296
Electric Susceptibility Studies of Cooperative Jahn-Teller Ordering in Rare-Earth Crystals....Pages 297-301
Neutron Scattering Studies of the Cooperative Jahn-Teller Effect....Pages 302-322
Gamma-Ray Diffraction Studies of the Mosaic Distribution in TmAsO 4 Near the Cooperative Jahn-Teller Transition at 6 K....Pages 323-326
The Central Peak in TbVO 4 ....Pages 327-330
The Nature of the Eigenfunctions in a Strongly Coupled Jahn-Teller Problem....Pages 331-336
Cooperative Pseudo Jahn Teller Model of the Sequence of Ferroelastic Transitions in Barium Sodium Niobate....Pages 337-344
Single Ion and Cooperative Jahn-Teller Effect for a Nearly Degenerate E Doublet....Pages 345-350
Study of the Mott Transition in n.Type CdS by Spin Flip Raman Scattering and Faraday Rotation....Pages 351-369
Electron Phonon Interactions and Charge Ordering in Insulators....Pages 370-392
The Verwey Transition in Magnetite....Pages 393-408
Back Matter....Pages 409-416

✦ Subjects

Science, general