The Metal-Nonmetal Transition in Magnetic Local Moment Systems

点击翻译按钮获取中文摘要

9802126 Dowben This is a collaborative focused research group proposal involving three principal investigators with complementary experimental skills. The research investigates the surface electronic and structural properties of manganese oxides and rare earth pnictnides (nitrides). These materials of considerable interest because they have a ferromagnetic transition that appears to accompany the non-metal to metal transition. However, the relation between the magnetic behavior and the electrical transport properties is now well understood. The goals of the program are to understand the nature of the non-metal to metal transition near the ferromagnetic transition, and to investigate how the surface ferromagnetic properties and metallically may differ from the bulk properties in these materials. The program will address important issues such a whether the surface magnetism precisely follows that of the bulk material. The program employs a large number of spectroscopic techniques and characterization tools to elucidate the electronic band structure, bulk transport properties and magnetic properties of the oxide and nitride materials. While this is fundamental research program the results of the project will be relevant to the general fields of magnetism and superconductivity. For example, surface magnetism and transport properties of oxide materials are fundamental issues in the field of information storage technology. %%% This is a collaborative focused research group proposal involving three principal investigators with complementary experimental skills. The research deals with the relationship between the surface and bulk properties of manganese oxide and rare earth nitride materials. In these materials, rapid changes in magnetic properties can occur simultaneously with large changes in the electrical conductivity are ob served. However, the relation between these two phenomena is not well understood. Further, the relation between the surface properties of the materials and the bulk properties is also an open question. This effort will combine a range of surface spectroscopic and structural techniques to obtain new information about magnetic and transport properties of these materials. Close collaboration with theorists at U Nebraska - Omaha, U Nebraska - Lincoln, and South Dakota School of Mines, and Case Western Reserve U will facilitate interpretation of the measurements. While this is fundamental research program the results of the project will be relevant to the general fields of magnetism and superconductivity. For example, surface magnetism and transport properties of oxide materials are fundamental issues in the field of information storage technology. ***