Size and temperature dependent stability and phase transformation in single-crystal zirconium nanowire

作者：Sutrakar Vijay Kumar^*; Mahapatra D Roy

来源：Journal of Nanoparticle Research, 2011, 13(10): 5335-5346.

DOI：10.1007/s11051-011-0519-4

• Molecular dynamics
• Phase transformations
• Nanowire
• Zirconium
• Nanostructured materials
• Stability
• Modeling and simulation

A novel size dependent FCC (face-centered-cubic) -> HCP (hexagonally-closed-pack) phase transformation and stability of an initial FCC zirconium nanowire are studied. FCC zirconium nanowires with cross-sectional dimensions < 20 are found unstable in nature, and they undergo a FCC -> HCP phase transformation, which is driven by tensile surface stress induced high internal compressive stresses. FCC nanowire with cross-sectional dimensions > 20 , in which surface stresses are not enough to drive the phase transformation, show meta-stability. In such a case, an external kinetic energy in the form of thermal heating is required to overcome the energy barrier and achieve FCC -> HCP phase transformation. The FCC-HCP transition pathway is also studied using Nudged Elastic Band (NEB) method, to further confirm the size dependent stability/metastability of Zr nanowires. We also show size dependent critical temperature, which is required for complete phase transformation of a metastable-FCC nanowire.

• 出版日期2011-10