2023年2月2日，以博士生张艺群同学为第一作者的论文“Local Displacive Phase Transformation in Large-magnetostriction Alloy Fe81Ga19”被形状记忆合金领域专业刊物SHAPE MEMORY AND SUPERELASTICITY录用！青年教师苟峻铭博士和博士生杨天子同学共同完成了该论文的部分工作。这也是2023兔年课题组被录用的首篇论文。祝贺她们！

ABSTRACT:

Soluting nonmagnetic Ga into body-centered-cubic (BCC) Fe has been found to create over tenfold enhancement in magnetostriction — a fundamental property of ferromagnetic materials, but the underlying origin remains elusive. It was shown that such extraordinary magnetostriction enhancement is closely related to lattice softening, analogous to the scenario of displacive/martensitic phase transformation. In this work, we report the {111}BCC collapse induced hexagonal ω phase in the magnetostriction-peak alloy Fe81Ga19. The local BCC to ω phase transformation was observed at highly-strained non-equilibrium state, where artificial-aging-induced tetragonal L60 intermediate phase and L12 equilibrium phase coexist with the BCC matrix. The mechanically harder L60/L12 phases exert strong shear stress along <111>BCC direction on the mechanically softer BCC matrix, leading to the formation of ω phase at the phase interface. This study provides new evidence for the lattice softening of Fe-Ga alloys, adding important insight into understanding their extraordinary magnetostriction effect.