Sreekala, S and Ananthakrishna, G (2005) Two-dimensional model for ferromagnetic martensites. In: Physical Review B, 72 (13).
We consider a recently introduced two-dimensional square-to-rectangle martensite model that explains several unusual features of martensites to study ferromagnetic martensites. The strain order parameter is coupled to the magnetic order parameter through a four-state clock model. Studies are carried out for several combinations of the ordering of the Curie temperatures of the austenite and martensite phases and,the martensite transformation temperature. We find that the orientation of the magnetic ordering, which generally points along the short axis of the rectangular variant, changes as one crosses the twin or the martensite-austenite interface. The model shows the possibility of a subtle interplay between the growth of strain and magnetic order parameters as the temperature is decreased. In some cases, this leads to qualitatively different magnetization curves from those predicted by earlier mean-field models. Further, we find that strain morphology can be substantially altered by the magnetic order. We have also studied the dynamic hysteres is behavior. The corresponding dissipation during the forward and reverse cycles has features similar to the Barkhausen'snoise.
|Item Type:||Journal Article|
|Additional Information:||Copyright for this article belongs to American Physical Society.|
|Department/Centre:||Division of Chemical Sciences > Materials Research Centre
Division of Physical & Mathematical Sciences > Physics
|Date Deposited:||12 Dec 2005|
|Last Modified:||19 Sep 2010 04:22|
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