Volume 91, Number 2, July 2010
|Number of page(s)||6|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||04 August 2010|
Cluster evolution in spin crossover systems observed in the frame of a mechano-elastic model
Department of Physics, Alexandru Ioan Cuza University - Blvd. Carol I 11, 700506, Iasi, Romania, EU
2 Computational Materials Science Center, National Institute for Materials Science - Tsukuba, Ibaraki, Japan
3 CREST, JST - 4-1-8 Honcho Kawaguchi, Saitama, 332-0012, Japan
4 Institute for Solid State Physics, the University of Tokyo - Kashiwa, Chiba, Japan
5 Department of Physics, Graduate School of Science, The University of Tokyo - Bunkyo-Ku, Tokyo, Japan
6 Département de Chimie Physique, Université de Genève - Switzerland
Accepted: 15 July 2010
In this paper we study the cluster formation and evolution in spin crossover systems during the thermal transition in the frame of a mechano-elastic model applied to open boundary hexagonal lattices. The switching processes between the high-spin (HS) and low-spin (LS) state are studied by a method combining a Monte Carlo standard procedure on the spin state and the lattice relaxation. In the present study, we adopt the transition probabilities of the spin state taking into account the energy gap between the two states, the degeneracy ratio and the local pressure determined by the elongations of the closest springs. It is found that clusters of molecules in the same state tend to grow starting from corners, as in available experimental data. Some qualitative differences between the processes of cluster formation for the two hysteresis branches, i.e., HS to LS and LS to HS are pointed out. Moreover, we have studied the dependence of cluster formation on the strength of the elastic interactions, and also on the system size. The size dependence of the ratio between the system size and the maximum cluster length is very weak, which indicates the appearance of macroscopic domains.
PACS: 75.30.Wx – Spin crossover / 64.60.-i – General studies of phase transitions / 75.60.-d – Domain effects, magnetization curves, and hysteresis
© EPLA, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.