Topology and elemental distribution in Co alloy:oxide perpendicular media

This analytical electron microscopy study was performed to understand better the microstructure of CoCrPt: SiO2 media. The topology of the magnetic Co alloy grains and the distribution of the elements in the thin films were of special interest. High angle annular dark field images revealed that many grains in the range 5-8 nm have a cavity in their center, observed by low mass-thickness contrast. Electron energy loss spectroscopy Co elemental mapping shows Co to be concentrated mainly in the grains with a depleted region in the center. Si, O, and Cr appear to strongly segregate to the grain boundaries and somewhat to the cavities. In this paper we discuss the possible grain growth mechanisms and the effect of the presence of such cavities on recording properties. (c) 2009 American Institute of Physics. [DOI: 10.1063/1.3057818]