Soft Magnetic Thin Films Composed of Ultra Fine Crystallites

Fe基纳米晶薄膜的软磁性能研究：采用溅射法制备了FeHFC薄膜和Fe/FeHFC多层薄膜。FeHFC在制备时为非晶态，热处理后转变为非晶态。即使没有热处理，Fe层也处于纳米晶状态。结果表明，两种薄膜均表现出优异的软磁性能。特别地，Fe/FeHFC多层膜由于Fe的高浓度而在高磁感应强度方面是上级的。另外。发现多层中的纳米结晶状态在高达约700 ℃的高温下是稳定的。Co-Fe/Cu和Co-X/Cu多层膜的巨磁电阻效应：磁致伸缩效应与Co中的合金元素有关，Fe的含量约为10at%时，磁致伸缩效应增强，大于Co/Cu多层膜的磁电阻效应。TbFe_2-B和SmFe_2-B非晶合金的磁致伸缩性能：采用高速烧结法制备的TbFe_2-B和SmFe_2-B非晶合金在低磁场（200 Oe时约为60 × 10 ↑ [3]）下均获得了很大的磁致伸缩<-6>。

Soft Magnetic Properties of Fe Based Nano-Crystalline Thin Films: FeHFC then films and Fe/FeHFC multilayered thin films were prepared by a sputter method. The FeHFC was amorphous in the as-prepared state, while it transformed into the mano-crystalline state by a heat treatment. The Fe layers were in the nano-crystalline state even without heat treatment. As a result, both the films showed excellent soft magnetic properties. Particularly, the Fe/FeHFC multilayers were superior in high magnetic induction, because of the high concentration of Fe. In addition. it was found that the nano-crystalline state in the multilayers was stable up to high temperatures as about 700ﾟC. The stability was thought to be attributed to the pinning effect of the HFC fine crystallites precipitated at the boundaries of Fe fine crystallites.Giant Magnetoresistance in Co-Fe/Cu and Co-X/Cu Multilayered Thin Films: It was found that the magnetostriction depended on the alloying elements into Co and about 10 at% of Fe gave rise to an enhanced magnetoresistance, larger than that of Co/Cu multilayer. Moreover, we succeeded to reduce the magnetic field for exciting magnetoresistance in the new multilayer of Co-Fe/Cu/Co-Fe.Magnetostriction in TbFe_2-B and SmFe_2-B Amorphous Alloys: Huge magnetostrictions saturated easyly in low magnetic fields (about 60 x 10^<-6> at 200 Oe) were obtained in TbFe_2-B and SmFe_2-B amorphous alloys prepared by a high rate sputtermethod.