BACKGROUND:  Developing spintronic devices has become increasingly popular in recent years. Critical to spintronic applications, magnetism in the material used needs to be of intrinsic nature and not associated with secondary phase structures. Mn doped Ge thin films exhibit promising ferromagnetic properties. However, with conventional growth methods secondary phases of MnXGe1-X clusters have been widely observed, resulting in undesirable metallic properties for spintronic applications.

INNOVATION:  Researchers at UCLA have developed a novel growth method for secondary-phase free MnGe thin films. Molecular beam epitaxy (MBE) is used to alter the growth of MnGe and GE thin layers, resulting in a "superlattice" structure that successfully avoids the formation of secondary phases. In particular, the method enables the formation of ordered and self-assembled MnGe nanostructures, such as MnGe nanodots, nanocolumns, and wells. Furthermore, the proposed growth method can be applied to other ferromagnetic material to achieve similar magnetic nanostructures, leading to new spintronic devices.

POTENTIAL APPLICATIONS 

• Magnetic nanostructures
• Spintronic devices
• Microelectronic devices

ADVANTAGES

• Free of secondary phases
• Applicable to wide range of ferromagnetic material
• Excellent controllability of self-assembeled nanostructures (nanodots, nanocolumns, wells)

Reference: UCLA Case No. 2009-721