Magnetic properis of Cr2AlC(Mn) thin films

• Applicants: Professor Dr.-Ing. Christoph Leyens; Professor Jochen M. Schneider, Ph.D.
• Subject Area: Coating and Surface Technology
• Term: from 2015 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 272363496

MAX phases in the form of thin films have recently attracted increased attention due to their crystal structure which combines a unique blend of metallic and ceramic properties. Cr2AlC is one of the most promising MAX phases for which a very good combination of high oxidation resistance and damage tolerance is obtained. The magnetic properties of the Cr2AlC have been neither experimentally nor theoretically previously investigated. From our own work it is known that the magnetic properties of the Cr2AlC layers are strongly dependent on the structure of the phase (solid solution or ordered nano-laminated structure).An important goal of this joint application is a quantitative determination of the relationships between the film production parameters, the structure and magnetic properties both of as deposited films and after thermal degradation (oxidation). The changes of the magnetic properties with the production and ageing process must be investigated in order to be able to develop a possible measurement method which can be used to help describe the state of the MAX phase thin films after production (in terms of quality control) and after use (in terms of controlling the condition of the layer). With this in mind a further goal of this work is to raise the transition temperature, which at the moment is in cryogenic temperature range, to room temperature. It is proposed that this will be achieved by doping of the Cr2AlC MAX phase with Mn. The experimental work is to be supported by and compared with thermodynamic calculations. A further goal of the proposal is to use the theoretical prediction and experimental evidence in order to control the magnetic properties of the Cr2AlC MAX phase and, thereby, increase its usage spectrum beyond that of a protective layer at higher temperatures in the direction of being a function layer.

• DFG Programme: Research Grants