Anisotropic kinetics of solid phase transition from first principles: alpha-omega phase transformation of Zr

作者：Guan, Shu-Hui; Liu, Zhi-Pan^*

来源：Physical Chemistry Chemical Physics, 2016, 18(6): 4527-4534.

DOI：10.1039/c5cp07299a

• SURFACE WALKING METHOD
• TOTAL-ENERGY CALCULATIONS
• STRUCTURE PREDICTION
• DIMER METHOD
• TITANIUM
• ZIRCONIUM
• PRESSURE
• STATE

Structural inhomogeneity is ubiquitous in solid crystals and plays critical roles in phase nucleation and propagation. Here, we develop a heterogeneous solid-solid phase transition theory for predicting the prevailing heterophase junctions, the metastable states governing microstructure evolution in solids. Using this theory and first-principles pathway sampling simulation, we determine two types of heterophase junctions pertaining to metal alpha-omega phase transition at different pressures and predict the reversibility of transformation only at low pressures, i.e. below 7 GPa. The low-pressure transformation is dominated by displacive Martensitic mechanism, while the high-pressure one is controlled by the reconstructive mechanism. The mechanism of alpha-omega phase transition is thus highly pressure-sensitive, for which the traditional homogeneous model fails to explain the experimental observations. The results provide the first atomic-level evidence on the coexistence of two different solid phase transition mechanisms in one system.

• 出版日期2016-2-14
• 单位复旦大学