Understanding of double-curvature shaped magnetoimpedance profiles in Joule-annealed and tensioned microwires at 8-12 GHz

作者：Popov V V; Berzhansky V N; Gomonay H V; Qin F X^*

来源：Journal of Applied Physics, 2015, 117(17): 17A322.

DOI：10.1063/1.4916185

We have investigated for the first time the combined effect of current and stress on the giant magnetoimpedance characteristics of vanishing-magnetostrictive Co-rich microwires at microwave frequency. As the current-annealed wire is subject to certain tensile stress, one can observe a drastic transformation of field dependence of magnetoimpedance (MI) profiles from smooth shape of a broad peak to deformed shape of a sharp peak with the emergence of a kink on each side. It follows that three different regions-core, inner, and outer shell-have been formed by the combined effect of Joule-annealing, current generated magnetic field, and the tensile stress. A critical field sees a drop of field sensitivity from outer to inner shell and shifts to lower value with increasing annealing current. We successfully adapted our core-shell model to a core-shell-shell model by designating different anisotropy fields for each region to satisfactorily resolve the unique double-curvature shaped peaks in the field derivative MI profiles.

• 出版日期2015-5-7