Effect of shields in perpendicular recording

Micromagnetic simulations have been used to investigate magnetization dynamics in a perpendicular recording head with a trailing shield. The numerical experiment was carried out on a set of head models with shields. Trailing shields used in modelling had a thickness of 20 nm and spacing of 50, 100 and 150 nm from the trailing edge of the tip. Results of our investigations show that shields not only increase the gradient of the recording field but also help to generate more surface charges on the tip and on the SUL below it. For specific configurations and head to shield spacing (>50 nm) this leads to higher field magnitudes, leading to the 4-6% increase in the perpendicular field at 10 nm below ABS.