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One detrimental by-product of heat-assisted magnetic recording writing is the creation of head contamination. Here, we present the current understanding of the driving forces, growth mechanisms, and growth rates of write-induced head contamination. The combination of an evaporation and condensation model with shear forces suggests a flow of lubricant on the head may precipitate contamination. The contamination is observed to grow in the head–media gap until it contacts the media surface, at which point an additional material pickup mechanism can be activated. Evidence of contact-induced transfer and a chemical reaction of the contamination is presented, and the impacts of contamination on head temperatures and thermal gradient is presented. Depending on the contamination properties, head temperatures may be increased substantially, leading to increased reliability risk. Consistent with previous analyses, we find that contamination may increase media thermal gradient. [ABSTRACT FROM AUTHOR]

Lubricant accumulation was found on the media surface the instant when the laser is turned OFF during heat-assisted magnetic recording write operations. By changing the write cycles, laser ON/OFF duration, media, and head temperatures, we find that this lubricant accumulation is related to the change in head–media temperatures. The observed lubricant deposition process is restricted to a short time window (1– 2~\mu \texts ) after the laser is turned OFF. An equilibrium model of thermal displacement due to evaporation and condensation processes is presented and used to discuss the effect of the head–media temperature changes on the lubricant accumulation. Possible solutions to minimize the lubricant transfer and deposition are discussed. [ABSTRACT FROM AUTHOR]