(University of Alabama Libraries, 2019) Abugri, Joseph Bukari; Gupta, Subhadra; University of Alabama Tuscaloosa
The development of new materials for spintronic applications, such as STT-MRAM, continues to expand at a rapid rate, attracting a great deal of research interest. Our group has tried to simplify the design of the perpendicular magnetic tunnel junction (pMTJ) stack by replacing the complex Co/Pd multilayer synthetic antiferromagnet pinning layer with a CoPd alloy. In my PhD work, I have studied systems in which these CoPd layers are used to pin the reference layers of pMTJs. We have examined the influence of composition, thickness, and seed layers on the coercivity, remanence and perpendicular anisotropy of CoPd alloys, and related them to their structural properties and switching behavior utilizing various characterization methods. Results utilizing First Order Reversal Curve (FORC) analysis, atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), magnetic force microscropy (MFM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) will be detailed in this dissertation. It will be clearly shown that improved magnetic properties depend upon improved crystal structure of the CoPd alloy, which in turn, depends upon the seed layer upon which it is grown.