Soft modes and structural phase transitions

Venkataraman, G. (1979) Soft modes and structural phase transitions Bulletin of Materials Science, 1 (3-4). pp. 129-170. ISSN 0250-4707

PDF - Publisher Version

Official URL:

Related URL:


This paper presents a survey of soft modes and their relationship to structural phase transitions. After introducing the concept of a soft mode, the origin of softening is considered from a lattice-dynamical point. The Landau theory approach to structural transitions is then discussed, followed by a generalisation of the soft-mode concept through the use of the dynamic order-parameter susceptibility. The relationship of soft modes to broken symmetry is also examined. Experimental results for several classes of crystals are next presented, bringing out various features such as the co-operative Jahn-Tellev effect. The survey concludes with a discussion of the central peak, touching upon both the experimental results and the theoretical speculations.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
ID Code:55768
Deposited On:19 Aug 2011 03:12
Last Modified:18 May 2016 07:54

Repository Staff Only: item control page