Synthesis of high functional Fe compound thin films NAME

近年来，人们开始考虑将渗碳体（Fe_3C）应用于超钢材料和低环境负荷钢材料。虽然钢是最古老的使用材料之一，但氧化铁、氮化物和碳化物的基本性质还没有完全了解。本课题组在国内率先成功制备了单相Fe_3C薄膜。采用电子阵雨法测定了Fe_3C （Hv1180O）的硬度和硬度与温度的关系。Fe_3C为亚稳相，在室温下，Fe_3C表面仍呈非晶态氧化膜。Fe_3C的耐蚀性是铁的两倍，而铁的耐蚀性没有那么高，但这种非晶氧化膜阻止了铁的腐蚀。结果表明，Fe_3C在室温下成为铁的保护膜。珠光体中的Fe_3C不仅薄膜在室温下被氧化，而且表面也被氧化。因此，在评价Fe_3C的性质时需要非常小心。我们也是第一个生产（Fe, Ni）_3C薄膜的公司。与纯Fe_3C相比，Ni/Fe比0.05 ~ 0.1的薄膜的饱和磁通密度是纯Fe_3C的1.4倍，居里温度高20 ~ 30k，硬度是纯Fe_3C的1.3倍。因此，添加第三种元素可以改善Fe_3C的性能。随着Ni含量的进一步增加，由于Ni不能完全溶解，导致性能恶化。（Fe, Ni）_3C膜的耐蚀性与含铁膜基本相同，但含镍膜的耐蚀性明显下降。真空蒸发法和活化反应蒸发法制备的α-Fe_2O_3膜附着力低，不具有保护膜作用。另一方面，电子阵雨PVD法制备的α-Fe_2O_3薄膜完全不脱落，可以作为保护膜。此外，经电子雨辐照的铁也不可靠。铁衬底表面存在FeO可能是造成这一现象的原因。电子阵雨辐照有望成为一种新的抗铁腐蚀方法。

Recently, application ofcementite (Fe_3C) to supersteel materials and to steel materials with low environmental load are considered. While steel is one of the oldest used materials fundamental properties of iron oxides, nitrides, and carbides are not fully understood. Our group was the first to succeed in producing single-phase Fe_3C film. Electron shower method was used, and hardness of Fe_3C (Hv1180O) and temperature dependency of hardness were obtained.Fe_3C was also found out to be a metastable phase, and the surface became a amorphous oxide film even when kept at room temperature. Corrosion resistance of Fe_3C is two times greater than iron which is not so high, but this amorphous oxide film stopped corrosion of iron. As a result, Fe_3C became a protection film of iron in room temperature. Also, not only thin filmsbut surface of Fe_3C in pearlite oxidized in room temperature. Thus, thorough care is required in appreciating properties of Fe_3C. We were also the first to produce (Fe, Ni)_3C films. Compared to pure Fe_3C, films with Ni/Fe ratio 0.05-0.1 had 1.4 times saturation magnetic flux density, 20-30K higher Curie temperature, and 1.3 times hardness. Thus, an addition of a third elementimproved properties of Fe_3C. Further increase of Ni content resulted in deterioration of properties since Ni cannot completely dissolve. (Fe, Ni)_3C films had almost same corrosion resistance withiron but corrosion resistance fell remarkably in presence of Ni metal. α-Fe_2O_3 films produced by vacuum evaporation method andactivated reactive evaporation had low adhesion and is not a protective film. On the other hand, α-Fe_2O_3 films produced by electron-shower PVD method did not peel off at all and could be used as protective film. In addition, iron irradiated with electron shower did notrust. Existence of FeO on surface of iron substrate is suggested to be the reason. Electron shower irradiation is expected to be a new method to resist corrosion of iron.