Materials and Thin Films for Spintronic Devices

Purdue University, West Lafayette IN

Investigators

Abstract

The project will be devoted to the growth of III-V diluted magnetic semi- conductors (III-V DMSs) ternary compounds in which the anions are re- placed with a member of the 3d-transition group. The motivation and goal of the program are to explore and establish the conditions for successful growth of single crystals which will be materials suitable for investigating the ex- traordinary physical phenomena originating in the large magnetic moments of 3d-transition-ion (3d-TMI) and their role as acceptors. The simultaneous presence of free holes and the large magnetic moments provide the ingredi- ents for novel phenomena associated with spin-polarized charge carriers. The growth will initially focus on the incorporation of Mn, Co and Fe into GaAs, InP, GaP and InSb by thermal diffusion and melt growth. Spectroscopic (Fourier Transform Infrared, Raman and photoluminescence, modulated re- flectivity/transmission and magneto optic characterization at Purdue and those based on magnetic, electron-paramagnetic-resonance, and non-linear spectroscopy by international collaborators will provide invaluable feedback to the crystal grower. Another collaboration will address the production of ultrapure starting material and fabrication of substrates suitable for molec- ular beam epitaxy (MBE). Basic science and device related work will be ini- tiated during this phase. Besides the crystal growth program implemented by the Co-PI, students will participate in the characterization activities and will acquire a healthy appreciation of growth techniques. This exposure and involvement will prepare them for the scientific/technical workforce of the 21st century. The aim of the program is to provide a "steady state-" supply of well characterized III-V diluted magnetic semiconductors to our ongoing research on collective and localized excitations of vibrational, electronic, and magnetic character. The access to bulk single crystals as well as material as MBE- grown epilayers and quantum well structures will give the participants the intense excitement of basic research significant in device applications.