We present an analytical model for calculating energy barrier for the magnetic field-driven domain wall-mediated magnetization reversal of a magneto-resistive random access memory (MRAM) cell and apply it to study thermal stability factor Δ for various thicknesses of W layers inserted into the free layer (FL) as a function of the cell size and temperature. We find that, by increasing W thickness, the effective perpendicular magnetic anisotropy (PMA) energy density of the FL film monotonically increases, but at the same time, Δ of the cell mainly decreases. Our analysis shows that, in addition to saturation magnetization Ms and exchange stiffness constant Aex of the FL film, the parameter that quantifies the Δ of the cell is its coercive field Hc, rather than the net PMA field Hk of the FL film comprising the cell.
@article{arxiv.2008.00412,
title = {Thermal stability for domain wall mediated magnetization reversal in perpendicular STT MRAM cells with W insertion layers},
author = {G. Mihajlovic and N. Smith and T. Santos and J. Li and B. D. Terris and J. A. Katine},
journal= {arXiv preprint arXiv:2008.00412},
year = {2021}
}