处理电流密度对钴基非晶薄带巨磁阻抗效应的影响

Influences of Different Electrical Current Density on Giant Magneto-impedance Effects of Co-based Amorphous Ribbons

本文研究了焦耳处理工艺的处理电流密度对Co68.15Fe4.35Si12.5B15和Co71.8Fe4.9Nb0.8Si7.5B15非晶薄带巨磁阻抗效应的影响。样品在不同电流密度下进行了处理。实验结果表明:焦耳处理存在最佳电流密度,对Co68.15Fe4.35Si12.5B15窄带来说,最佳处理电流密度为30A/mm2,处理后样品的阻抗变化率峰值和灵敏度分别为119%和73%/Oe;对Co71.8Fe4.9Nb0.8Si7.5B15窄带来说,最佳处理电流密度为35A/mm2,处理后的阻抗变化率峰值为232%,灵敏度在30A/mm2时达到42%/Oe。处理后样品的内应力得到有效释放,软磁性能提高,使薄带的巨磁阻抗效应较淬态时有了明显提高。处理电流密度是焦耳处理方法中影响钴基非晶薄带巨磁阻抗效应的一个重要参数。

The influences of electrical current density of Joule heating treatment on GMI effects of amorphous Co68.15Fe4.35Si12.5B15 and Co71.8Fe4.9Nb0.8Si7.5B15 soft magnetic ribbons were studied. The samples were annealed under different electrical current density. The result shows that Joule heating treatment exists optimal electrical current density, the optimal electrical current density is 30A/mm^2 for Co68.15Fe4.35Si12.5B15 ribbons, the maximal magnetoimpedance ratio and sensitivity of the samples annealed after different electrical current density is 119 % and73 %/Oe respectively. The optimal electrical current density is 35A/mm^2 for Co68.15Fe4.35Si12.5B15 ribbons, the maximal magnetoimpedance ratio and sensitivity （the electrical current density being 30 A/mm^2） of the samples annealed after different electrical current density is 232 % and42 %/Oe respectively. The inner stress of the samples annealed after different electrical current density was released, the soft magnetic properties was improved, so the maximal GMI effect has been obtained. The results show that the electrical current density is a very important parameter that affects the giant maggneto-impedance effect of ribbons in Joule heating treatment method.