Reversal mechanism in perpendicular media with columnar structure

A contribution is given to the discussion concerning the nature of the magnetization reversal process in sputtered CoCr recording media with columnar morphology. The paper is restricted to the additional effects on the total perpendicular anisotropy by studying the columnar shape anisotropy and the properties of the perpendicular hysteresis loop (shearing and coercivity). On the basis of experiments and calculated results the conclusion is made that the columnar shape anisotropy has no significant influence and a final remark is that a strict particle model cannot account for the magnetic properties of CoCr layers and that a domain wall model offers a better alternative.