Ferromagnetic metal/semiconductor hybrid structures for magnetoelectronics

We report on the following new ferromagnetic metal/semiconductor heterostructure material systems: (1) $\mathrm{Fe/InAs}\text{(100)-4×2,}$ (2) Fe/InAs(graded)/GaAs(100), and (3) Fe/InAs/AlSb/GaSb/AlSb/InAs/GaAs resonant tunneling diodes. Single crystal Fe films have been stabilized in these structures using molecular beam epitaxy growth, as evidenced by low energy electron diffraction. The magnetic and electrical properties have been studied using in situ (and focused) magneto-optical Kerr effect, alternating gradient field magnetometry, and current–voltage measurements. The results show that Fe/InAs based heterostructures are very promising systems for use in future magnetoelectronic devices as they have well defined magnetic properties as well as favorable electrical properties.