Probe and control of low-power photo-excited magnetization precession in Co/Pd multilayer films

Abstract

Co/Pd thin film multilayers show large Perpendicular Magnetic Anisotropy (PMA) which is useful in MRAM devices for perpendicular magnetic recording. Co/Pd systems have been studied extensively through the use of ultrafast optical pump-probe methods in order to measure the Time Resolved Photo-excited Precession of Magnetization (TRPEPM). Most studies have been conducted at high laser fluence (> 1 mJ/cm2), where heating near the curie temperature occurs. In this study, we present low fluence measurements between 0.42 to 3.14 μJ/cm2 in Co/Pd systems with differing Co thickness between 0.4 to 0.74 nm to probe the role of interface anisotropy in low-power excitation.