Development of In-Situ Magnetic Characterization for Magnetic/Semiconductor Heterostructures Research, Student Training and Education

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

0076493 Palmstrom This is an award for the development of an in-situ magnetic characterization system that will interconnect to an in-situ atomic level growth and characterization facility. The new instrument will allow magnetic and spin polarization measurements to be made at different stages of magnetic/semiconductor heterostructure growth. These magnetic measurements will be correlated with in-situ structural and elemental studies to obtain a fundamental understanding of ferromagnetic/semiconductor heterostructures and interfaces. The instrument will also be used for in-situ magnetotransport and electroluminescence measurements to determine spin transport across ferromagnetic/semiconductor heterojunctions and magnetoresistance of ferromagnetic epitaxial layers. In designing and developing this instrumentation the students and postdoctoral associates will learn to work as a team and be exposed to multiple disciplines ranging from low temperature and semiconductor physics, superconductivity, optics, magnetics, and UHV practices to molecular beam epitaxy, surface and materials science. This is an award for instrument development at the university of Minnesota-Twin Cities. The possibility of manipulating and detecting the spin of an electron in addition to its charge is the key to the development of "Spintronics", which integrates magnetic and semiconductor materials. However, the detailed knowledge of both the magnetic and electronic properties of ferromagnetic/semiconductor interfaces, is needed to understand and control the electron spin as it crosses the interface. The development of a in-situ magnetic characterization will allow magnetic, magneto-optic and magnetotransport properties of magnetic/semiconductor single crystal structures to be studied during their formation from subatomic layer to micrometer thicknesses as they are grown by molecular beam epitaxy without exposing the structures to air. During this project, students and postdoctoral associates will be acquire skills in experimental techniques (ultra-high vacuum technology, magnetics, optics, cryogenics, superconductivity, electronics, mechanical design and materials processing) as well as in understanding the underlying physics (role of atomic structure at surfaces and interfaces and in the bulk of materials on the magnetic properties of thin films and the spin polarized transport across interfaces between magnetic materials and semiconductors).