arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0809.2640cond-mat.mtrl-sci
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结构相变的中间态:单组分序参量与应变耦合的模型

Intermediate states at structural phase transition: Model with a one-component order parameter coupled to strains

Akihiko Minami, Akira Onuki

摘要:

本文研究了一个二维结构相变的Ginzburg-Landau模型,其中一个序参量耦合到四元应变和膨胀应变。自由能中的这种弹性耦合项对相变行为影响很大,特别是在三临界点附近。一个典型的特征是中间态的出现,其中有序和无序区域在介观尺度上共存于温度窗口中的近稳态。窗口宽度随着膨胀耦合强度的增加而增加。它是由非均匀应变中相序的冻结引起的。不涉及杂质机制。我们提出了一个简单的理论的中间状态,以产生符合模拟结果的相图。

英文摘要:

We study a Ginzburg-Landau model of structural phase transition in two dimensions, in which a single order parameter is coupled to the tetragonal and dilational strains. Such elastic coupling terms in the free energy much affect the phase transition behavior particularly near the tricriticality. A characteristic feature is appearance of intermediate states, where the ordered and disordered regions coexist on mesoscopic scales in nearly steady states in a temperature window. The window width increases with increasing the strength of the dilational coupling. It arises from freezing of phase ordering in inhomogeneous strains. No impurity mechanism is involved. We present a simple theory of the intermediate states to produce phase diagrams consistent with simulation results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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