Scatter Diagram Analysis of Cr Segregation in Co–Cr Based Recording Media

The segregation of Cr in Co–Cr based thin film recording media was measured using energy-filtered TEM images and quantitatively evaluated by the scatter diagram (SD) method. Following a description of such SD analysis it is applied to the measurement of Cr segregation in two CoCrPtB thin film recording media with different Cr contents. Taking the entire data sets into account, the two dimensional distribution of the nonmagnetic, high Cr phase can be visualized and determined quantitatively. Cr segregates to the intergranular regions and the sample with the higher Cr content shows a significantly higher and more uniform distribution of the nonmagnetic phase at the boundaries. This leads to better magnetic isolation between the grains and correlates with the better recording performance observed in the same sample.