Direct Experimental Demonstration of Bend-Induced Transformation of Magnetic Structure in Amorphous Microwires

In the pursuit of active elements for bending and curvature sensors, magneto-optical investigations were performed on bent microwires. For the first time, local surface magnetization reversal curves were obtained from various sides of bent Co-rich and Fe-rich microwires. The observed differences in surface magnetization reversal behavior are directly attributed to the transverse distribution of internal mechanical stresses, which range from maximum tensile stress on the outer side of the bent sample to maximum compressive stress on the inner side. Depending on the sample composition and the nature of local stress, distinct magnetic structures-axial, elliptical, and spiral-were identified in different locations on the surface of the microwire. These findings provide valuable insights into the operational mechanisms of bending-sensitive magnetic sensors.