Surface Effects on Structural Phase Transformations in Nanosized Shape Memory Alloys

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• 作者：Zhen Zhang ; Xiangdong Ding ; Junkai Deng ; Jian Cui ; Jun Sun ; Tetsuro Suzuki ; Kazuhiro Otsuka ; Xiaobing Ren
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：April 18, 2013
• 年：2013
• 卷：117
• 期：15
• 页码：7895-7901
• 全文大小：450K
• 年卷期：v.117,no.15(April 18, 2013)
• ISSN：1932-7455

文摘

We systematically investigated the role of surface on the B2鈥揃19 transformation of free-standing nanoparticles by classical molecular dynamics simulations. It was found that the surface of particles has a shell structure with a thickness of 2 unit cells, suppressing the B2鈥揃19 transformation locally. Below a critical size, this surface shell leads to the reduction of the transformation latent heat and the vanishing of B2鈥揃19 transformation. We propose a Landau-type model based on the core鈥搒hell structure of particles, which reproduces well the relation between transformation temperature and particle size. Our results provide a microscopic insight into the origin of surface-induced size effect on the structural phase transformations in nanosized shape memory alloys.