HIGH-FREQUENCY SOFT MAGNETIC PROPERTIES AND MAGNETIC DOMAIN STRUCTURES OF ULTRATHIN Co-BASED AMORPHOUS RIBBONS

研究了真空制备超薄钴基非晶带的高频磁性能，并利用克尔效应观察了其畴型。样品为零磁致伸缩（(Fe-Co)Cr_y）_x(Si-B)_<100-x'> (x=75 ~ 81), （y=0.05 ~ 0.06）非晶合金。所得结果如下：(1)通过横向场退火，样品的磁芯损耗在100 kHz以上时极低。在6.0 mm厚（（Fe-Co)Cr_<0.06>）_<79>(Si-B)_<21>）的带状磁芯中，最大磁通密度B_m=0.1T时，1mhz损耗为700 （mW/cc）。这一数值约为Mn-Zn高频铁氧体或5 mum Supermalloy带绕磁芯的1/4。（2)此外，（Fe-Co）Cr_y）_x(Si-B)_<100-x'> (x=76-81)带状的初始磁导率的频率依赖性也得到了显著改善。(3)利用Kerr效应观察到一些超薄带的畴图。研究了横向磁场退火对磁性能的影响，并讨论了其与提高高频性能的关系。

High-frequency magnetic properties of ultrathin Co-based amorphous ribbons fabricated in vacuum were studied and their domain patterns were observed by the Kerr effect. The samples used were zero magetostrictive ((Fe-Co)Cr_y)_x(Si-B)_<100-x'> (x=75-81), (y=0.05-0.06) amorphous alloys. The results obtained were as follows.(1) Extremely low core loss beyond 100 kHz was attained for the samples with a transverse field annealing. In the case of 6.0 mum thick ((Fe-Co)Cr_<0.06>)_<79>(Si-B)_<21> ribbon cores, the loss at 1 MHz for maximum flux density B_m=0.1T was 700 (mW/cc). This value was about 1/4 of that of Mn-Zn high-frequency ferrites or 5 mum Supermalloy tape wound cores.(2) Furthermore, marked improvements of frequency dependence of initial permeability were also obtained for ((Fe-Co)Cr_y)_x(Si-B)_<100-x'> (x=76-81) ribbons with transverse field annealing.(3) The domain patterns of some ultrathin ribbons were observed by the Kerr effect. The effect of transverse magnetic field annealing on the magnetic properties was also studied and their relation to the improvement of high-frequency properties was discussed.