Key properties obtained for transition temperature.
The martensitic transition temperature (MTT) of a shape-memory alloy (SMA) is one of its most important characteristics determining its operating temperature. The energy difference (Δ𝐸) between the austenite and martensite phases is among the most crucial factors dictating MTT. Using density-functional theory, Δ𝐸 of NiTi, the most studied and commonly used SMA, varies from 23 to 116 meV/atom, depending on the density functional [Wu and Lawson, J. Chem. Phys. 161, 134104 (2024)]. Consequently, free-energy calculations using different density functionals yield MTTs that differ by several hundred K. In this work Δ𝐸 of NiTi was obtained using diffusion quantum Monte Carlo. The energy difference is estimated to be 70.9±2.5 meV/atom.
Kevin K. Ly, Zhigang Wu, and John W. Lawson. Phys. Rev. B 113, 184115 (2026). https://doi.org/10.1103/gf27-pcl6
