Theoretical investigations of cobalt/platinum alloys and supercells
Description
In this work I have studied a number of technologically important magnetic materials using density functional theory. Two ab-initio methods have been employed to investigate several ferromagnetic materials, the Vienna ab-initio Simulation Package and the layer Korringa-Kohn-Rostoker Method. The systems studied include two series of L10 alloys, and Co3Pt (both form natural superlattices) as well as artificially grown Co1Pt5 superlattices. Experimental difficulties associated with the growth of L10 alloys is discussed, along with theoretical calculations of the magnetic properties as a function of content. Another candidate for perpendicular data storage, the orthorhombic derivative Pmm2 phase of Co 3Pt, has also proven difficult to grow as it appears to be metastable. The possibility of phase stabilization has been explored using first principles methods. In a collaborative effort to improve micromagnetics simulations, the way in which local magnetic properties are affected near grain boundaries of Co1Pt5 supercells has been examined. Results of these first principles calculations have been used as input parameters in micromagnetics simulations. Both the first principles calculations and specifics of the micromagnetic simulations are discussed, in addition to calculations of Cr buffer layers acting to magnetically decouple grains. Conclusions are drawn as to the achievement of the stated research goals