Laser-Induced Thermo-Desorption of Perfluoropolyether Lubricant from the Surface of a Heat-Assisted Magnetic Recording Disk: Lubricant Evaporation and Diffusion
- 234 Downloads
- 4 Citations
Abstract
Heat-assisted magnetic recording (HAMR) storage technology will thermally stress the lubricant film typically applied to the storage disk surface. Different lubricant loss and morphology change mechanisms have been hypothesized to occur during information writing. A loss to of the lubricant film will dramatically affect its overall mechanical and chemical performance of the head–disk interface, decreasing its reliability and its durability. Thus an all optical pump–probe method was used to study the effect of fast thermal transients (106 K/s) on a lubricant film on HAMR media. Thermal transients (Bhushan and Cheng in J Appl Phys 81:5390, 1997) with peak temperatures above the HAMR media Curie temperature (T c) were found to remove by evaporation the lubricant within the heated region creating a lubricant depression in the otherwise continuous film. No accumulation of lubricant volume was observed to take place in the cooler regions of the thermal spot, indicating that thermocapillary shear stress is not an important mechanism of lubricant thickness change with the optical spot size used (65 μm). The onset of lubricant loss was observed to begin at approximately 610 K and was totally removed at 823 K. The change in depth of the lubricant depression with time showed that no structural terms contributed to the disjoining pressure for the lubricant thickness range studied. From this change, the diffusion coefficient of the lubricant on the carbon overcoat surface was determined to be 1 × 10−13 m2/s by fitting Fick’s second law to the normalized lubricant thickness. The importance of these observations on the operating HAMR head–disk interface is discussed.
Keyword
Magnetic data storage Surface diffusion Lubricant evaporationReferences
- 1.Bhushan, B., Cheng, Y.: Wear degradation mechanisms of magnetic thin-film rigid disks with different lubricants using mass spectrometry. J. Appl. Phys. 81, 5390 (1997)CrossRefGoogle Scholar
- 2.Seagate Promises to Double HDD Capacity With HAMR. http://www.storagenewsletter.com/rubriques/hard-disk-drives/seagate-hamr/ (2012)
- 3.Challener, W., Erden, M.F., Gage, E., Hsia, Y.-T., Ju, G., Kryder, M., McDaniel, T., Rottmayer, R.: Heat assisted magnetic recording. Proc. IEEE 96(11), 1810 (2008)CrossRefGoogle Scholar
- 4.Herrera-Fierro, P., Jones Jr, W.R., Pepper, S.V.: Interfacial chemistry of a perfluoropolyether lubricant studied by X-ray photoelectron spectroscopy and temperature desorption spectroscopy. J. Vac. Sci. Technol. A 11(2), 354 (1993)CrossRefGoogle Scholar
- 5.Waltman, R.J.: The interactions between Z-Tetraol perfluoropolyether and amorphous nitrogenated-and hydrogenated-carbon surfaces and silicon nitride. J. Fluor. Chem. 125, 391–400 (2004)CrossRefGoogle Scholar
- 6.Heller, J., Mate, C.M., Tam, A.C.: Laser-induced short time scale thermal chemistry of perfluoropolyether lubricant films. Langmuir 15, 82–8287 (1999)CrossRefGoogle Scholar
- 7.Ma, Y., Chen, X., Liu, B.: Experimental study of lubricant depletion in heat-assisted magnetic recording: effect of the duration of one laser heating. Tribol. Lett. 48, 337–344 (2012)CrossRefGoogle Scholar
- 8.Zhou, W., Zeng, Y., Liu, B., Yu, S., Hua, W., Huang, X.: Evaporation of polydisperse perfluoropolyether lubricants in heat-assisted magnetic recording. Appl. Phys. Express 4, 095201–095203 (2011)CrossRefGoogle Scholar
- 9.Ma, Y.S., Chen, X.Y., Zhao, J.M., Yu, S.K., Liu, B., Seet, H.L., Ng, K.K., Hu, J.F., Shi, J.Z.: Experimental study of lubricant depletion in heat assisted magnetic recording. IEEE Trans. Magn. 48(5), 1813–1818 (2012)CrossRefGoogle Scholar
- 10.Wu, L.: Modelling and simulation of the lubricant depletion process induced by laser heating in heat-assisted magnetic recording system. Nanotechnology 18, 215702-215701–215702-215708 (2007)Google Scholar
- 11.Tagawa, N., Kakitani, R., Tani, H., Iketani, N., Nakano, I.: Study of lubricant depletion induced by laser heating in thermally assisted magnetic recording systems-effect of lubricant film materials. IEEE Trans. Magn. 45(2), 877–882 (2009)CrossRefGoogle Scholar
- 12.Tagawa, N., Tani, H.: Lubricant depletion characteristics induced by rapid laser heating in thermally assisted magnetic recording. IEEE Trans. Magn. 47(1), 105–110 (2011)CrossRefGoogle Scholar
- 13.Chen, X., Ma, Y., Liu, B., Xie, H., Ji, R.: Experimental study if lubricant depletion in heat assisted magnetic recording: different lubricants On HAMR media. Microsyst. Technol. 19(9–10), 1581–1586 (2013)CrossRefGoogle Scholar
- 14.Tagawa, N., Andoh, H., Tani, H.: Study on lubricant depletion induced by laser heating in thermally assisted magnetic recording systems: effect of lubricant thickness and bonded ratio. Tribol. Lett. 37, 411–418 (2010)CrossRefGoogle Scholar
- 15.Tagawa, N., Miki, T., Tani, H.: Depletion of monolayer liquid lubricant films induced by high-frequency pulsed-laser heating in thermally assisted magnetic recording. Microsyst. Technol. 18, 1353–1357 (2012)CrossRefGoogle Scholar
- 16.Waltman, R.J., Deng, H., Wang, G.J., Zhu, H., Tyndall, G.W.: The effect of PFPE film thickness and molecular polarity on the pick-up of disk lubricant by a low-flying slider. Tribol. Lett. 39(2), 211–219 (2010)CrossRefGoogle Scholar
- 17.Waltman, R.J., Khurshudov, A.G.: The contribution of thin PFPE lubricants to slider-disk spacing. 2. Effect of film thickness and lubricant end groups. Tribol. Lett. 13(3), 197–202 (2002)CrossRefGoogle Scholar
- 18.Jones, P.M., Merzikline, A., Yan, X., Li, L., Dinh, L., Stirniman, M., Tang, H.: The influence of ultraviolet irradiation on the surface chemistry of Ztetraol magnetic hard disk lubricant: a combined temperature programed desorption and X-ray photoelectron spectroscopic study. Tribol. Lett. 44(2), 201–211 (2011)CrossRefGoogle Scholar
- 19.Lei, R.Z., Gellman, A.J., Jones, P.: Thermal stability of Fomblin Z and Fomblin Zdol thin films on amorphous hydrogenated. Carbon 11(1), 1–5 (2001)Google Scholar
- 20.Solvay-Solexis: Fomblin Z Derivatives: Product Data Sheet. Solvay Solexis, Inc., North America (2002)Google Scholar
- 21.Jones, P.M., Ahner, J., Platt, C.L., Tang, H., Hohlfeld, J.: Understanding disk carbon loss kinetics for heat assisted magnetic recording. IEEE Trans. Magn. 50(3), 3300704 (2014)CrossRefGoogle Scholar
- 22.Daahl, J.B., Bogy, D.B.: Lubricant flow and evaporation model for heat-assisted magnetic recording including functional end-group effects and thin film viscosity. Tribol. Lett. 52, 27–45 (2013)CrossRefGoogle Scholar
- 23.Zeng, Y., Zhou, W., Huang, X., Yu, S.: Numerical study on thermal-induced lubricant depletion in laser heat-assisted magnetic recording systems. Int. J. Heat Mass Transf. 55, 886–896 (2012)CrossRefGoogle Scholar
- 24.Lim, M.S., Gellman, A.J.: Kinetics of laser induced desorption and decomposition of Fomblin Zdol on carbon overcoats. Tribol. Int. 38, 544–561 (2005)CrossRefGoogle Scholar
- 25.Marchon, B., Karis, T.E.: Poiseuille flow at a nanometer scale. Europhys. Lett. 74(2), 294–298 (2006)CrossRefGoogle Scholar
- 26.Marchon, B., Saito, T.: Lubricant thermodiffusion in heat assisted magnetic recording. IEEE Trans. Magn. 48(11), 4471–4474 (2012)CrossRefGoogle Scholar
- 27.Castellanos, A.J., Garcia-Sucre, M., Urbina-Villalba, G.: Temperature dependence of hamaker constants for fluorocarbon compounds. J. Phys. Chem. B 107, 8532–8537 (2003)CrossRefGoogle Scholar
- 28.Kim, M.C., Jhon, M.S.: Microscopic spreading of nonreactive perfluoropolyalkylether film on amorphous carbon surfaces. Korean J. Chem. Eng. 17(4), 44448 (2000)Google Scholar
- 29.Mayeeda, M.S., Kato, T.: Experimental study of the replenishment of ultrathin liquid perfluoropolyether films on carbon surfaces. J. Appl. Phys. 91(10), 7580–7582 (2002)CrossRefGoogle Scholar
- 30.Tagawa, N., Korenaga, M., Mori, A., Kobayashi, N., Ikegami, M.: Effects of end groups on the spreading characteristics of molecularly thin liquid lubricant films in hard disk drives. IEEE Trans. Magn. 43(9), 3705–3709 (2007)CrossRefGoogle Scholar
- 31.Kim, M.C., Lee, S.B., Kim, S.: Microscopic spreading characteristics of nonpolar perfluoropolyalkylether film on carbon surfaces. J. Ind. Eng. Chem. 8(1), 39–45 (2002)Google Scholar
- 32.Itoh, S., Takahashi, K., Fukuzawa, K., Amakawa, H., Zhang, H.: Spreading properties of monolayer lubricant films: effect of bonded molecules. IEEE Trans. Magn. 45(11), 5055–5060 (2009)CrossRefGoogle Scholar
- 33.Ma, X., Gui, J., Grannen, K., Marchon, B., Jhon, M.S., Bauer, C.L.: Spreading of perfluoropolyalkylether films on amorphous carbon surfaces. J. Chem. Phys. 110(6), 3129–3137 (1999)CrossRefGoogle Scholar
- 34.George, S.M.: Surface diffusion measured using laser induced desorption. In: Proceedings of the International Conference on Lasers ‘84. STS Press, McLean, VA, USA (1985)Google Scholar
- 35.Waltman, R.J.: Autophobic dewetting of Z-tetraol perfluoropolyether lubricant films on the amorphous nitrogenated carbon surface. Langmuir 20, 3166–3172 (2004)CrossRefGoogle Scholar
- 36.Karis, T.E., Kim, W.T., Jhon, M.S.: Spreading and dewetting in nanoscale lubrication. Tribol. Lett. 18(1), 27–41 (2005)CrossRefGoogle Scholar