Current dependence of the magnetization rise time in thin film heads

Time-domain optical measurements of magnetization dynamics can now be performed with sufficient resolution to reveal the intrinsic speed of many structures relevant to magnetic recording. Here we describe the behavior of the magnetization rise time at the air-bearing surface of a thin film recording head, as a function of the amplitude of current pulses in the write coil. The spatial profile of the magnetization on both sides of the gap is also examined through time-resolved, current dependent measurements. Spatial resolution enhancement via a solid immersion lens allows domain features to be discerned in the data.