Microwave stress monitoring using Co-rich amorphous microwire assessed by free space measurements

We provide new experimental results on studies on effect of applied stress on Reflection coefficient ( S 22 parameter) of Co-rich glass-coated ferromagnetic microwire measured using free space microwave spectroscopy. Studied Co-rich microwire with vanishing magnetostriction coefficient presents high Giant magnetoimpedance, GMI, effect associated with excellent soft magnetic properties. Tensile stress was applied through the mechanical load, attached to the single Co-rich microwire sample inside the anechoic chamber and the S 22 parameter was measured at 2.45 GHz using broadband horn antennas and a vector network analyzer. Upon tensile stress (up to 225 MPa) we observed substantial change in the S 22 parameter. The change in the S 22 parameter correlates with the stress dependence of hysteresis loops. The experimentally discovered stress dependence of the reflection coefficient allows for contactless stresses and damage monitoring of in composites with microwire inclusions. • Substantial effect of applied stress on the Reflection coefficient (S 22 parameter) at GHZ range of Co-rich glass-coated ferromagnetic microwire. • An increase in the magnetic anisotropy field and a decrease in the magnetic susceptibility upon applied tensile stress in studied microwires. • Correlation of the stress dependencies of S 22 parameter and hysteresis loops modification upon applied stress. • Change in the hysteresis loop shape of Co-rich glass-coated microwires upon applied stress