Phase transition with non-deterministic nature in the Ni₃Al_0.45V_0.50 alloy

¹  Research Department, NISSAN ARC, LTD. - Yokosuka, Kanagawa 237-0061, Japan
²  Department of Photonic and Electronic Systems, Waseda University - Shinjuku, Tokyo 169-8555, Japan

Corresponding author: tanimura@nissan-arc.co.jp

Received: 22 January 2008
Accepted: 7 April 2008

Abstract

We demonstrate a thermodynamic state change dominated by a non-thermodynamic variable found in the Ni₃Al_0.45V_0.50 alloy. Specifically, the L1₂ L1₂ + 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.