Imanging Magnetic Domian Morphologies of Cobalt/Platinum Multilayer Thin-films*

I am doing research under Dr. Chesnel at Brigham Young University. The research studies the magnetic domain morphologies of CoPt thin-films ranging from 55-335 nanometers in total thickness. In these CoPt multilayer thin-films, the thickness of the individual Co layers varies in the samples from 0.4 to 6 nanometers and the thickness of the individual Pt layer is 0.7 nanometers, these two layers repeat 50 times. I will present results for samples with a Co thickness of 2.5 and 3.1 nanometers.

We used a Vibrating Sample Magnetometer (VSM) to apply a strong magnetic field looping sequence to the samples before returning to net-zero magnetization. We then used an Atomic Force Microscope (AFM) to map the magnetic domain morphologies. We repeated this process, of alternatively using the VSM and AFM to complete various types of sequences.

The densities of the magnetic domains of the individually and previously applied loops in each state were analyzed. I am looking for the relationship between the magnitude of the previously applied magnetic field and the density of the magnetic domains in three different types of series. I will present a comparison between the ascending series, the descending series, and the pumping series.