Room-temperature ultrasensitive magnetoelastic responses near the magnetic-ordering tricritical region

The morphotropic phase boundary (MPB) has been recently extended from ferroelectrics to ferromagnets, especially for giant magnetostrictive materials. The giant magnetostrictive system in turn presents abundant research opportunities on MPB investigation. In this work, we demonstrate that a magnetic-ordering tricritical type MPB near room temperature can be constructed in the Tb xHo 1 - x(Fe 0.9Co 0.1) 2 magnetostrictive system. An ultrahigh magnetostrictive sensitivity is obtained that achieves the performance of the commercial Tb 0.27Dy 0.73Fe 2 (Terfenol-D) polycrystal in the Tb 0.2Ho 0.8(Fe 0.9Co 0.1) 2 alloy. The detailed domain microstructures near the magnetic-ordering tricritical region are determined using phase-field simulations. Our results provide the underlying insights of magnetic-ordering tricritical MPB needed to guide the design of ultrasensitive magnetostrictive materials.