Structures and Magnetic Properties of Iron Nano-Crystals Embedded in Ceramic Glass Films

近年来，镶嵌在绝缘基体中的纳米磁性颗粒由于其自旋相关的磁阻效应（即隧道型磁阻效应）而引起了人们的广泛关注。然而，很少有人研究磁性颗粒的纳米结构和形貌，如磁性颗粒的晶体结构、取向、尺寸、平均颗粒间距离和分布，与颗粒之间的磁相互作用及其磁性能之间的关系。（1）采用电子束蒸发法在Al_2O_3绝缘薄膜上沉积了Fe和Co纳米粒子。并根据电子显微镜观察到的纳米颗粒膜的结构和形貌讨论了它们的磁性。此外，在本研究中，（2）制造了一个“转移室”，它将在蒸发室中形成的纳米颗粒膜直接转移到电子显微镜中，而不会在空气中氧化或污染样品。

In recent years nano-granular magnetic particles embedded in insulating matrix has been attracting much interest, because of the appearance of spin-related magnetic resistance (MR) effect called "tunneling-type MR effect". However, little investigations have been made which relate nano-structures and morphologies of the magnetic particles, such as crystal structure, orientation, size, average inter-particle distance and distribution of magnetic particles, to magnetic interactions between the particles and their magnetic properties.In the present study, (1) Fe and Co nano-particles were deposited onto insulating Al_2O_3 films by electron-beam evaporation under various substrate temperatures and evaporation conditions. And their magnetic properties were discussed on the basis of structures and morphologies of the nanogranular films observed by electron microscopy. Also in this study, (2) a "transfer-chamber" was manufactured which transfers nano-granular films formed in an evaporation chamber directly into an electron microscope without specimen oxidation or contamination in air.