Bragg diffraction at structural phase transitions: a molecular dynamics study

Content Provider	Scilit
Author	Mair, S. L.
Copyright Year	1986
Description	Journal: Journal of Physics C: Solid State Physics The temperature dependences of the mean square displacements and order parameters have been calculated using molecular dynamics for a series of ferrodistortive and antiferrodistortive phase transitions for two-dimensional lattices of varying size. The model system consists of a multiple-minimum effective one-particle potential centred on each lattice site and harmonic nearest-neighbour coupling. By allowing the walls of the one-particle potential to be quadratic the experimentally observed linear temperature dependence of the mean square displacements at high temperatures can be reproduced. Choosing as the origin the equilibrium atomic position for the high-temperature phase, the mean square displacements are observed to be smooth across the phase transition, $T_{c}$ occurring in the vicinity of the point of inflection. This behaviour is in agreement with scaling theory, although mean-field theory predicts a spurious cusp-singularity at $T_{c}$. Comparisons are made with experimental data and with one-dimensional models.
Related Links	http://iopscience.iop.org/article/10.1088/0022-3719/19/32/008/pdf
Ending Page	6338
Page Count	18
Starting Page	6321
ISSN	00223719
DOI	10.1088/0022-3719/19/32/008
Journal	Journal of Physics C: Solid State Physics
Issue Number	32
Volume Number	19
Language	English
Publisher	IOP Publishing
Publisher Date	1986-11-20
Access Restriction	Open
Subject Keyword	Journal: Journal of Physics C: Solid State Physics Condensed Matter Physics Molecular Dynamic Mean Field Theory Mean Square Displacement Phase Transition
Content Type	Text
Resource Type	Article
Subject	Physics and Astronomy Condensed Matter Physics Engineering