This Science in Developing Countries award will help to support a research collaboration between Professor James Erskine of the University of Texas at Austin and Professor Jose Araya-Pochet of the University of Costa Rica. The researchers intend to explore the relationship between atomic level structure and magnetism, and to probe fundamental concepts in phase transitions. The project will investigate electronic and magnetic properties of matter that are intrinsic to thin film structures, surfaces, and interfaces. The experimental approach will combine novel materials synthesis, advanced structure determination methods, and spin sensitive spectroscopic techniques. The proposed work is driven by new capabilities to deliberately modify and characterize physical properties of matter that affect magnetic behavior, and by recent improvements in magnetically sensitive spectroscopic techniques. These experienced collaborators will use the latest instrumentation at the University of Texas and at the National Synchrotron Light Source at Brookhaven National Laboratory to pursue the goals of the project.