Premonitory effects near critical transition temperature in ordering systems – a Monte Carlo simulation

Abstract

Premonitory effects manifest themselves in an ordering transition of the first kind (order) in the form of anomalously high short-range order (SRO) intensity at temperatures marginally above T _c, the critical transition temperature. This intensity located at the superlattice positions of the long-range ordered (LRO) phase is often attributed to the formation of ‘heterophase fluctuations’ resembling clusters of the LRO phase. Monte Carlo simulations in a hypothetical system showing FCC-to-L1₂ ordering transition have been carried out here to shed some light on this phenomenon and to look into the atomic configurations that make up these fluctuations.

Keywords:

• Monte Carlo simulation
• premonitory effects
• short-range ordering
• diffuse intensity
• heterophase fluctuations

Acknowledgements

This work was carried out under the Joint Research Project of Japan–India Science Cooperative Program of the Department of Science and Technology (DST), India and Japan Society for the Promotion of Science (JSPS).