InSn seedlayers for Co∕Pd multilayered media were engineered using dopants (Pd, O) to achieve grain size of 7.8±1.8nm(σ=23%) and virgin magnetic cluster size of less than 65nm. HN=−5kOe and Hc=12.2kOe make this media promising for extremely high-density recording. These parameters were all realized with room-temperature depositions without annealing. Media with O-doped 2-nm InSn seedlayers without other adhesion layers achieved Hc=6.2kOe, which will be beneficial in reducing spacing loss. There is evidence that the engineered seedlayers also reduce the anisotropy dispersion and therefore the switching field distributions of these media.

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A typical way to analyze anisotropy dispersion (σHk) in perpendicular magnetic recording media is to simply calculate the slope parameter α(dM∕dH) from a hysteresis loop. However, α is also dependent on intergranular exchange, and is therefore not an accurate measure of σHk. In this work, σHk and intergranular exchange were varied in high coercivity Co∕Pd multilayers on InSn seed layers in order to determine their relationship with coercivity, saturation magnetization, and α. These parameters were altered using various concentrations of oxygen as measured by Auger sputter depth profiles, and a minor loop coercivity method was used to find σHk independent of exchange. A general cross-referencing analysis was developed to characterize the important parameters of media using hysteresis loops. And in this study, the analysis showed that oxygen in Co-Pd multilayers reduced intergranular exchange coupling as expected, but it also increased σHk at higher concentrations.