非晶Co基软磁合金巨磁阻抗效应研究

GIANT MAGNETO-IMPEDANCE EFFECT IN CO-RICH AMORPHOUS ALLOY RIBBON

巨磁阻抗可应用于微型高灵敏度磁传感器．我们研究了三种非晶合金薄带的巨磁阻抗效应．实验表明，在一定频率范围内提高测试频率，磁阻抗效应有明显提高；适当温度的退火也有助于磁阻抗效应的提高．其中成分为Ｃｏ７０Ｆｅ４．５Ｎｉ４Ｎｂ１Ｓｉ１２．５Ｂ８的非晶合金带的效应最显著，制备态非晶样品在频率为 ５ＭＨｚ下达 １２０％左右，经过退火处理的非晶样品在 ５ＭＨｚ下的效应可达４００％左右。

Giant magneto-impedance effects have prompted potential applications in magnetic sensors and especially in magnetic recording heads. The GMI effects have been observed in two Co-Rich amorphous ribbons and a Fe-Rich alloy ribbon. It is shown that the GMI effects increase with driving current frequency and an appropriate annealing can enhance the effect. A large MI ratio of about 120% in as-cast sample of amorphous Co70 Fe4.5Ni4Nb1Si12.5B8 alloys and a ratio of about 400% in a suitably annealed sample have been measured at 5MHz.