Thin films - A. Markou
In the recent years, Heusler compounds have attracted a lot of interest in the field of spintronics. The predicted half-metallic character of some of these compounds, i.e. they are 100% spin polarized at the Fermi level EF, make them very promising for future applications such as MRAM (magnetic random access memory) or STT (spin transfer torque) devices.
From the applicational point of view the fabrication of thin films is absolutely indispensable for a successful implementation of such new materials into devices. Since sputter deposition is the main preparation technique for large scale production our aim is the development of novel Heusler compounds in a thin film by sputtering.
While the "classical" Heusler compounds have a cubic crystallograpic structure (L21 for X2YZ and C1b for XYZ compounds), the directed design of new materials with tailored physical properties also utelizes their relatives with e.g. tetragonal distorted unit cells as found in Mn3-xGa compounds. Due to their great tunabilty of magnetic moment, magnetocrystalline anisotropy and Gilbert damping constant, while possessing a high spin polarization and a high Curie temperature, the main compositions under investigation are Mn2-based.
Beside our research on magnetic materials, we are also active in the field of topological insulators. In particular, the fabrication of novel compounds with predicted topological insulating properties, their optimization with regard to the electronic structure and their integration into hetereostructures to allow the advanced study of transport properties, such as the tunneling into superconductors, is targeted within the priority programm 1666.