Investigation of Transition Metal Impurities by Weak Localization and the Anomalous Hall Effect

这个项目是关于贵金属或简单（s,p）金属表面的nd-原子的磁性。采用弱局域化和反常霍尔效应的互补输运方法。这些方法检测磁性杂质原子与体/表面传导电子之间的磁相互作用。弱定位技术允许检测不到10-4的单层表面原子，并且比其他检测方法灵敏100倍。反常霍尔效应测量有助于确定磁性原子的性质，是铁磁性的还是反铁磁性的。本项目涉及磁性杂质原子与传导电子之间耦合的实验和理论两个方面。三维原子的亚单层，以及四维和五维原子，如锆、钼、锝和钌，在银和金等金属上的亚单层将被研究。这些结果不仅具有根本性的意义，而且在微电子工业等技术领域也有潜在的应用前景。对薄膜和表面磁性的研究属于材料研究的一个非常活跃的领域，有许多机会对诸如磁记录装置之类的技术产生影响。单个磁性原子构成了磁性结构中最简单的构件。这些原子将在本研究中使用非常灵敏的技术进行研究。其中一种技术可以检测到沉积在金属表面的磁性原子层的万分之一以下，另一种技术能够区分沉积原子的单个磁矩的方向。实验还探讨了表面的磁性在多大程度上与本体的磁性不同。＊＊＊

9509875 Bergmann This project is concerned with the magnetic properties of nd- atoms on the surface of noble metals or simple (s,p) metals. The complementary transport methods of weak localization and the anomalous Hall effect are employed. These methods detect the magnetic interaction between the magnetic impurity atoms and bulk/surface conduction electrons. The weak localization technique allows the detection of less that 10-4 of a monolayer of surface atoms, and is by a factor of 100 more sensitive than alternative detection methods. The anomalous Hall effect measurements help to determine the character of the magnetic atom, ferromagnetic or antiferromagnetic. This project addresses both experimental and theoretical aspects of the coupling between magnetic impurity atoms and conduction electrons. Sub-monolayers of 3d atoms, as well as 4d and 5d atoms such as zirconium, molybdenum, technetium, and ruthenium on metals such as silver and gold will be investigated. The results are of fundamental interest, but also have potential applications to technological areas such as the microelectronics industry. %%% The study of magnetism in thin films and on surfaces belongs to a very active area of materials research with numerous opportunities to have an impact on technology such as magnetic recording devises. Individual magnetic atoms form the simplest building blocks on magnetic structure. Such atoms will be investigated in this study using very sensitive techniques. On of these can detect less than one ten-thousandth of a single layer of magnetic atoms which are deposited on a metallic surface another technique is able to distinguish the direction of the individual magnetic moments of the deposited atoms. The experiments also probe to what extent the magnetic properties of surfaces differ from those of the bulk. ***