Applications of Micromagnetic Simulations for Use in the Development of Novel Magnetic Computer Memory

Traditional transistor memory has saturated all areas of the computer memory market, but leaves much to be desired in certain applications, opening opportunities for new and exciting technologies. In this thesis I expand the existing capabilities of the Physics of Nanomagnetic Materials and Devices lab by informing experimental decisions with the results from micromagnetic simulations, assisting with the ongoing goal of developing novel designs of STT-MRAM. In particular, I investigate and optimize the impact and interplay of each of the known magnetic phenomena and properties on the behaviour of magnetoresistive memory: saturation magnetization, anisotropy, exchange stiffness, interlayer exchange coupling, and thermal stability. Performance is judged quantitatively, considering switching current, switching fields, structure size, and homogeneity of states. This work uses magnum.pi, a proprietary Python library for solving micromagnetic problems using finite-element methods, developed by the Physics of Funct onal Materials lab of the University of Vienna. Simulated results show that reasonably sized structures undergo magnetic reversal noncoherently and that it is possible to reliably achieve and control a wide range of interlayer angles in synthetic antiferromagnets with careful choices of realistic anisotropy and other material parameters. Finally, simulations show that particular ranges of interlayer coupling strengths lead to substantially decreased switching currents.