J. Phys. IV France 112 (2003) 223
Displacive transformation of virus protein crystalS. Celotto and R.C. Pond
Materials Science and Engineering, Department of Engineering, University of Liverpool, Brownlow Hill, Liverpool L69 3BX, U.K.
A crystalline protein undergoes a displacive transformation in the T-even bacteriophage. In the present work, the transformation mechanism is modelled in terms of interfacial dislocations whose motion gives rise to the observed deformation. The topological properties (Burgers vector, , and `overlap' step height, h) of the dislocations involved are defined rigorously and a recent theory is used that quantifies the diffusional flux arising due to their movement. The circumstance under which passage of transformation dislocations is diffusionless is identified. Thus, dislocation modelling is used successfully to describe a diffusionless displacive transformation in a process where the phenomenological theory of martensite crystallography cannot be applied.
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