Tailoring ferroic domains by introducing internal stress: Fe₈₁Ga₁₉ magnetostrictive alloy as an example

Ferroic materials, including ferromagnets, ferroelectrics, and ferroelastics, can output strain via domain reversal stimulated by external fields. However, domains with multiple orientations generally form in ferroic materials, resulting in a small value of output strain. Tailoring the preferential orientation of ferroic domains is important for realizing large strain. In this work, taking Fe₈₁Ga₁₉ magnetostrictive alloys as an example, the preferential orientation of magnetic domains was realized by introducing unidirectional internal stress during single crystal growth. As a result, a large magnetostriction of 300 ppm which was close to the theoretical value of the Fe₈₁Ga₁₉ alloy was obtained from the single crystal without the application of bias pre-stress. After 10⁶ magnetization cycles, the magnetostriction was unchanged, exhibiting high stability. This work may supply an effective approach to tailor ferroic domains towards large strain and some other physical effects in ferroic materials.