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A model solid-state structural transformation: Tetragonal to Orthorhombic

Madan Rao·Surajit Sengupta
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Abstract

We study equilibrium properties of a system of particles in two dimensions, interacting with pair and three body potentials, which undergoes a structural transition from a square to a rhombic lattice and thus constitutes a simple model for a generic tetragonal to orthorhombic transition. We aim at an intermediate level of description lying in-between that of coarse grained elastic strain hamiltonians and microscopic ab-initio approaches. Macroscopic thermodynamic properties and phase diagram at zero and finite temperatures as a function of the density and the relative strengths of the pair and three body energies are obtained using lattice sums, an approximate `cell-model' theory and molecular dynamics simulations in the NVT ensemble. We propose that this model solid can be used as a test bed for studies of statics and dynamics of structural transitions.

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Madan Rao, Surajit Sengupta. 2001-06-05. A model solid-state structural transformation: Tetragonal to Orthorhombic. https://doi.org/10.1088/0953-8984%2F16%2F43%2F013

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