2017/09/21 by Dustin M. Lattery, Lattery, Dustin M., Delin Zhang +7 · 5 citations
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties and Applications #Magnetic properties of thin films #Magneto-Optical Properties and Applications #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · pdf · doi:10.48550/arxiv.1709.07483
openalex publication_date 2017/09/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Perpendicular magnetic materials with low damping constant and high thermal stability have great potential for realizing high-density, non-volatile, and low-power consumption spintronic devices, which can sustain operation reliability for high processing temperatures. In this work, we study the Gilbert damping constant (α) of perpendicularly magnetized W/CoFeB/MgO films with a high perpendicular magnetic anisotropy (PMA) and superb thermal stability. The α of these PMA films annealed at different temperatures is determined via an all-optical Time-Resolved Magneto-Optical Kerr Effect method. We find that α of these W/CoFeB/MgO PMA films decreases with increasing annealing temperature, reaches a minimum of α = 0.016 at an annealing temperature of 350 °C, and then increases to 0.024 after post-annealing at 400 °C. The minimum α observed at 350 °C is rationalized by two competing effects as the annealing temperature becomes higher: the enhanced crystallization of CoFeB and dead-layer growth occurring at the two interfaces of the CoFeB layer. We further demonstrate that α of the 400 °C-annealed W/CoFeB/MgO film is comparable to that of a reference Ta/CoFeB/MgO PMA film annealed at 300 °C, justifying the enhanced thermal stability of the W-seeded CoFeB films.