Performances of double layer medium in perpendicular recording

The dependence of recording performance on the medium parameters in a perpendicular recording system, composed of an auxiliary pole driven head and a double layer medium, is discussed. The soft magnetic back layer behaves as part of the head to enhance the magnetic interaction between the auxiliary pole and the main pole. For excessively thick back layer and Co-Cr layer, the reproduced output decreases due to shielding effect and weakened interaction. Since the main pole head parameters also closely relate to the recording performance, it was concluded that the medium and head design should be concurrently carried out.