First-principles calculations of thermal properties of the mechanically unstable phases of the PtTi and NiTi shape memory alloys

چکیده مقاله :
The design of shape memory alloys (SMA) demands detailed knowledge of their thermodynamic
properties and of the underlying atomic-level mechanisms governing their shape-memory behavior. This
knowledge is traditionally obtained via atomistic simulations, but these systems have so far resisted such
efforts due to the presence of phonon instabilities and associated spontaneous symmetry breaking. In
this study, we investigate the thermodynamics of PtTi, a novel and promising SMA (and of the related
better-known NiTi SMA, for comparison purposes) using recently developed first-principles computational
method specifically designed to tackle this issue. The method efficiently explores the system's
potential energy surface by discrete sampling of local minima, combined with a continuous sampling of
the vicinity of these local minima via a constrained harmonic lattice dynamic approach. Our calculations
provide a complete and atomic-level-based model for these compounds' free energy and shed some light
on the ongoing search for the precise structure of dynamically stabilized high temperature phases in
SMAs.

توضیحات تکمیلی :

مقاله ISI انگلیسی اصلی
سال انتشار:2018
فایل ISI انگلیسی اصلی ، با فرمت Pdf
تعداد صفحات فایل ISI انگلیسی اصلی: 8 صفحه

نویسندگان/توضیحات : Sara Kadkhodaei*, Axel van de Walle
تاریخ ارسال : 1397/10/07
تعداد بازدید : 352
کلمات کلیدی : First-principles calculations of thermal properties of the mechanically unstable phases of the PtTi and NiTi shape memory alloys (مقاله ISI - سال انتشار:2018)
تعداد صفحات : 8
نظرات کاربران در مورد این آگهی
در حال حاضر هیچ نظری ثبت نگردیده است .
ارسال پیام