Understanding Electronic and Magnetic Interactions in Complex Mixed Metal Chalcogenides

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Non-technical Abstract The ability to create new magnetic semiconductors in which the "up" or "down" magnetic spin orientation of conducting electrons can be controlled and manipulated through "on" or "off" electrical charge at ambient temperature could lead to smaller spin-based electronics (spintronics) for faster data processing, ultra-high-density data storage and low power consumption. With the support of the Solid State and Materials Chemistry program, the research team will use a combination of experimental and computational techniques to create new ferromagnetic semiconductors with flexible crystal structure and to investigate the nature of interactions between magnetic spin of free-carriers and localized magnetic atoms within these compounds that enables stable spintronic properties at room temperature. The discovery of such compounds could pave the way to next-generation computing in which data storage and processing functionalities are integrated on a single chip. The multidisciplinary nature of this project enables outstanding training of graduate students, undergraduate interns, high-school students and high-school teachers. Technical Abstract Engineering the atomic structure of an inorganic semiconductor to create isolated one-dimensional ferromagnetic subunits embedded within the semiconducting crystal lattice can enable (1) electronic manipulation of the ferromagnetic coupling strength within individual magnetic domains and (2) magnetic control of electronic transport within the semiconducting framework. Such atomic-scale integration of ordered magnetic and semiconducting domains in the same crystal structure enables independent investigation and understanding of the interactions between free-carrier spins and localized magnetic moments within these new classes of ferromagnetic semiconductors (FMSs). In this project, the research team combines advanced growth and characterization techniques with first-principles calculations to investigate FMSs based on transition-metal chalcogenides. The goal is to elucidate the mechanism by which charge carriers mediate or induce coupling between localized magnetic substructures embedded in the same crystal lattice in order to achieve exotic combinations of properties such as large magnetic moments, large coercivity, high Curie temperature and high electrical conductivity within a single material. Such a result would significantly advance our knowledge about the nature of coupling between electronic properties and magnetism, which is of tremendous importance to further expansion of research on spintronic materials.