Pole-tip protrusion effect on high data rate recording performance

Write pole-tip protrusion (PTP) effect on the overwrite performance at high recording data rate is discussed. It is shown that the head thermal expansion during the write process may lead to the degradation of overwrite value at high recording data rate. Overwrite degradation is caused by head-disk interactions when a high-frequency pattern is written. Appropriate selection of the disk lubricant can reduce the effect of the write PTP and increase the write current setting margin. At elevated drive temperatures, excessive PTP can cause head-disk interface failure. A write timing method allowing for the recording head to cool between the write cycles is proposed. A method of head-disk interface testing and a method of mapping the head-disk interactions are further described.