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Micomagnetic modeling is used to evaluate the effect of trailing edge shield (TES) magnetic properties on the dynamic performance of a writer used in perpendicular magnetic recording with wrapped around shield at air bearing surface. The gradient of the field increased with the increase in the TES saturation flux density and thickness; however the writer bubble width and field decreased as more flux turned toward the TES. The improvement of gradient can be vital for recording as the field can be traded-off until it's just above the media switching field helping form sharp transitions between bits and reduce the bit-error-rate. The reduction in the bubble width enables higher track density. Additionally, the manipulation of the anisotropy in TES can help increase the gradient further, promoted by easier flux flow. [ABSTRACT FROM AUTHOR]

Three partially built hard disk writer structures with active coil windings located at different positions relative to the yoke were studied by time resolved scanning Kerr microscopy. All three Cartesian components of the magnetization were recorded simultaneously. Time resolved signals recorded near the pole tip showed that the component of magnetization parallel to the driving field had the same rise time irrespective of the location of the coil winding, but largest amplitude when the active coil was located near the middle of the yoke. Dynamic images obtained from three devices showed “flux beaming” in a channel parallel to the driving field. The magnetic contrast was strongest when the active coil was located near the centre of the yoke, while relaxation after removal of the excitation was most complete when the active coil was located near the confluence region. These results confirm the need for a multiturn coil to ensure effective flux propagation along the entire length of the yoke. [ABSTRACT FROM AUTHOR]