Phase transition with non-deterministic nature in the Ni₃Al _0.45V_0.50 alloy

We demonstrate a thermodynamic state change dominated by a non-thermodynamic variable found in the Ni₃ Al_0.45 V _0.50 alloy. Specifically, the L1₂→L1 ₂+D0₂₂ evolution, which is a sub-phenomenon of the fcc→L1₂+D0₂₂ phase transition, takes place only when lattice defects are introduced to more than a certain critical density in the L1₂ diffusion field. Because the defect density changes along with the variation in the thermodynamic path, the path variation can alter the evolved state even under an identical thermodynamic condition. This path dependence of the state change shows the non-deterministic (chaotic) nature of the phase transition.