中文摘要：

研究了Fe36Co36Nb4Si4.8B19.2合金薄带为磁芯的螺线管（FeCo基磁芯螺线管）的巨磁阻抗效应与磁芯长度之间的关系.研究结果表明,磁芯长度是影响FeCo基磁芯螺线管巨磁阻抗效应的重要因素.当磁芯长度小于螺线管长度时,磁芯螺线管巨磁阻抗的最大值（ΔZ/Z）max与磁芯长度呈线性关系,其线性相关系数可以根据电磁学理论推导得到;当磁芯的长度大于螺线管的长度时,由于漏磁作用,（ΔZ/Z）max与磁芯长度的关系偏离了线性关系,（ΔZ/Z）max与磁芯长度的关系曲线中有一个极值点,（ΔZ/Z）max在极值点达到最大.磁芯螺线管巨磁阻抗效应曲线的尖刺部分高度（ΔZ/Z）T与磁芯长度的关系也有类似的极值点,（ΔZ/Z）T在极值点达到最大值.磁芯螺线管巨磁阻抗效应曲线的尖刺部分对弱磁场敏感,受磁芯退磁场的影响明显,磁芯的退磁场与磁芯长度呈负指数关系.

英文摘要：

The relation between the length of the magnetic core （l） and the giant magnetoimpedance（GMI） effect of solenoid with magnetic core of Fe36 Co36 Nb4Si4.8 B19.2 ribbon which annealed with current 32 A/mm2 for 10 min,has been investigated.The result shows that there is a sensitive relation between l and GMI.There is a linear relation between the l and the maximum of the GMI （ΔZ/Z）max when l is smaller than the length of the solenoid l0.The linear correlation coefficient can be deduced from the electromagnetism theory.It should deviate from the linear relation when l is greater than l0.There is a maximum value of the （ΔZ/Z）max when the l reaches the best value.There is a similar relation between the height of the tip like part of the GMI profile （ΔZ/Z）T and l.There is a maximum value of the （ΔZ/Z）T when the l is the best value.The tip like part of the GMI profile,which responds to the weak magnetic field sensitively,is influenced by the demagnetizing field.There is a negative exponential relation between the demagnetizing field and the length of the magnetic core l.