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A Description of Multiscale Modeling for the Head-Disk Interface Focusing on Bottom-Level Lubricant and Carbon Overcoat Models

DOI: 10.1155/2013/794151

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The challenges in designing future head disk interface (HDI) demand efficient theoretical modeling tools with flexibility in investigating various combinations of perfluoropolyether (PFPE) and carbon overcoat (COC) materials. For broad range of time and length scales, we developed multiscale/multiphysical modeling approach, which can bring paradigm-shifting improvements in advanced HDI design. In this paper, we introduce our multiscale modeling methodology with an effective strategic framework for the HDI system. Our multiscale methodology in this paper adopts a bottom to top approach beginning with the high-resolution modeling, which describes the intramolecular/intermolecular PFPE-COC degrees of freedom governing the functional oligomeric molecular conformations on the carbon surfaces. By introducing methodology for integrating atomistic/molecular/mesoscale levels via coarse-graining procedures, we investigated static and dynamic properties of PFPE-COC combinations with various molecular architectures. By bridging the atomistic and molecular scales, we are able to systematically incorporate first-principle physics into molecular models, thereby demonstrating a pathway for designing materials based on molecular architecture. We also discussed future materials (e.g., graphene for COC, star-like PFPEs) and systems (e.g., heat-assisted magnetic recording (HAMR)) with higher scale modeling methodology, which enables the incorporation of molecular/mesoscale information into the continuum scale models. 1. Introduction The continuous increase in the areal recording density specification beyond 1?Tb/in2 has led to ever decreasing head media spacing (HMS) requirements at the head disk interface (HDI). The key material components of the HDI are the carbon overcoat (COC) and lubricant layers, which protect the magnetic media from corrosion and tribological damage. Perfluoropolyethers (PFPE) with both functional and nonfunctional groups are standard HDI lubricants due to their low vapor pressure and low surface tension as well as good chemical and thermal stability. To make a more reliable product, improved lubricant and COC materials must have self-healing capability and lubricant-COC adhesion in addition to molecularly thin spreading layer thickness. The challenges involved in designing improved HDI materials require efficient theoretical modeling tools which allow flexibility in investigating various pairs of PFPE-COC materials. Due to the broad range of time and length scales of interest in the HDI components, a multiscale/multi-physical modeling approach can

References

[1]  D. Kim, P. S. Chung, P. Jain, S. H. Vemuri, and M. S. Jhon, “Multiscale modeling of head disk interface,” IEEE Transactions on Magnetics, vol. 46, no. 6, pp. 2401–2404, 2010.
[2]  L. J. Chen, H. J. Qian, Z. Y. Lu, Z. S. Li, and C. C. Sun, “An automatic coarse-graining and fine-graining simulation method: application on polyethylene,” The Journal of Physical Chemistry B, vol. 110, no. 47, pp. 24093–24100, 2006.
[3]  J. Fish, “Bridging the scales in nano engineering and science,” Journal of Nanoparticle Research, vol. 8, no. 5, pp. 577–594, 2006.
[4]  O. Al-Khayat and H. P. Langtangen, “Computational aspects of multiscale simulation with the lumped particle framework,” Communications in Computational Physics, vol. 12, pp. 1257–1274, 2012.
[5]  A. Lyubartsev, Y. Tu, and A. Laaksonen, “Hierarchical multiscale modelling scheme from first principles to mesoscale,” Journal of Computational and Theoretical Nanoscience, vol. 6, no. 5, pp. 951–959, 2009.
[6]  F. Muller-Plathe, “Coarse-graining in polymer simulation: from the atomistic to the mesoscopic scale and back,” ChemPhysChem, vol. 3, no. 9, pp. 754–769, 2002.
[7]  A. B. Mhadeshwar and D. G. Vlachos, “Hierarchical multiscale mechanism development for methane partial oxidation and reforming and for thermal decomposition of oxygenates on Rh,” Journal of Physical Chemistry B, vol. 109, no. 35, pp. 16819–16835, 2005.
[8]  T. Murtola, A. Bunker, I. Vattulainen, M. Deserno, and M. Karthunen, “Multiscale modeling of emergent materials: biological and soft matter,” Physical Chemistry Chemical Physics, vol. 11, pp. 1689–1892, 2009.
[9]  N. Sheng, M. C. Boyce, D. M. Parks, G. C. Rutledge, J. I. Abes, and R. E. Cohen, “Multiscale micromechanical modeling of polymer/clay nanocomposites and the effective clay particle,” Polymer, vol. 45, no. 2, pp. 487–506, 2004.
[10]  S. P. Xiao and T. Belytschko, “A bridging domain method for coupling continua with molecular dynamics,” Computer Methods in Applied Mechanics and Engineering, vol. 193, no. 17–20, pp. 1645–1669, 2004.
[11]  Q. Shi, S. Izvekov, and G. A. Voth, “Mixed atomistic and coarse-grained molecular dynamics: simulation of a membrane-bound ion channel,” Journal of Physical Chemistry B, vol. 110, no. 31, pp. 15045–15048, 2006.
[12]  K. Kremer and F. Müller-Plathe, “Multiscale simulation in polymer science,” Molecular Simulation, vol. 28, no. 8-9, pp. 729–750, 2002.
[13]  H. Wang, C. Junghans, and K. Kremer, “Comparative atomistic and coarse-grained study of water: what do we lose by coarse-graining?” The European Physical Journal E, vol. 28, no. 2, pp. 221–229, 2009.
[14]  R. Smith, P. Seung Chung, J. A. Steckel, M. S. Jhon, and L. T. Biegler, “Force field parameter estimation of functional perfluoropolyether lubricants,” Journal of Applied Physics, vol. 109, no. 7, Article ID 07B728, 2011.
[15]  J. M. Seminario, “Calculation of intramolecular force fields from second-derivative tensors,” International Journal of Quantum Chemistry, vol. 60, no. 7, pp. 1271–1277, 1996.
[16]  E. Anderson, Z. Bai, C. Bischof et al., LAPACK Users’ Guide, SIAM, Philadelphia, Pa, USA, 1999.
[17]  J. Wang, R. M. Wolf, J. W. Caldwell, P. A. Kollman, and D. A. Case, “Development and testing of a general Amber force field,” Journal of Computational Chemistry, vol. 25, no. 9, pp. 1157–1174, 2004.
[18]  R. L. Smith, P. S. Chung, S. H. Vemuri, G. Y. Yeom, L. T. Biegler, and M. S. Jhon, “Atomistic simulation method in head-disk interface of magnetic data storage systems,” Journal of Applied Physics, vol. 111, no. 7, Article ID 07B717, 3 pages, 2012.
[19]  P. S. Chung, H. Park, and M. S. Jhon, “The static and dynamic responses of binary mixture perfluoropolyether lubricant films- molecular structural effects,” IEEE Transactions on Magnetics, vol. 45, no. 10, pp. 3644–3647, 2009.
[20]  Q. Guo, P. S. Chung, M. S. Jhon, and H. J. Choi, “Nano-rheology of single unentangled polymeric lubricant films,” Macromolecular Theory and Simulations, vol. 17, no. 9, pp. 454–459, 2008.
[21]  H. Chen and M. S. Jhon, “Relationship between surface coverage and end group functionality of molecularly thin perfluoropolyether films,” Journal of Applied Physics, vol. 103, no. 7, Article ID 07F536, 3 pages, 2008.
[22]  P. S. Chung, H. Chen, and M. S. Jhon, “Molecular dynamics simulation of binary mixture lubricant films,” Journal of Applied Physics, vol. 103, no. 7, Article ID 07F526, 3 pages, 2008.
[23]  Q. Guo, P. S. Chung, H. Chen, and M. S. Jhon, “Molecular rheology of perfluoropolyether lubricant via nonequilibrium molecular dynamics simulation,” Journal of Applied Physics, vol. 99, no. 8, Article ID 08N105, 3 pages, 2006.
[24]  R. M. Balabin, “Communications: intramolecular basis set superposition error as a measure of basis set incompleteness: can one reach the basis set limit without extrapolation?” Journal of Chemical Physics, vol. 132, no. 21, Article ID 211103, 4 pages, 2010.
[25]  R. Smith, P. S. Chung, S. H. Vemuri, L. T. Biegler, and M. S. Jhon, “Atomistically tuning lubricant adhesion on carbon overcoat surface,” IEEE Transactions on Magnetics, vol. 48, no. 11, pp. 4273–4276, 2012.
[26]  S. Ghosh, W. Bao, D. L. Nika et al., “Dimensional crossover of thermal transport in few-layer graphene,” Nature Materials, vol. 9, no. 7, pp. 555–558, 2010.
[27]  W. R. Zhong, M. P. Zhang, B. Q. Ai, and D. Q. Zheng, “Chirality and thickness-dependent thermal conductivity of few-layer graphene: a molecular dynamics study,” Applied Physics Letters, vol. 98, no. 11, Article ID 113107, 3 pages, 2011.
[28]  A. Agarwal, L. T. Biegler, and S. E. Zitney, “Simulation and optimization of pressure swing adsorption systems using reduced-order modeling,” Industrial and Engineering Chemistry Research, vol. 48, no. 5, pp. 2327–2343, 2009.
[29]  W. G. Noid, J. W. Chu, G. S. Ayton et al., “The multiscale coarse-graining method. I. A rigorous bridge between atomistic and coarse-grained models,” Journal of Chemical Physics, vol. 128, no. 24, Article ID 244114, 11 pages, 2008.
[30]  S. Izumisawa and M. S. Jhon, “Stability analysis of ultra-thin lubricant films with chain-end functional groups,” Tribology Letters, vol. 12, no. 1, pp. 75–81, 2002.
[31]  R. J. Waltman, G. W. Tyndall, and J. Pacansky, “Computer-modeling study of the interactions of Zdol with amorphous carbon surfaces,” Langmuir, vol. 15, no. 19, pp. 6470–6483, 1999.
[32]  P. H. Kasai and A. M. Spool, “Z-DOL and carbon overcoat: bonding mechanism,” IEEE Transactions on Magnetics, vol. 37, no. 2, pp. 929–933, 2001.
[33]  R. J. Waltman, D. J. Pocker, and G. W. Tyndall, “Studies on the interactions between ZDOL perfluoropolyether lubricant and the carbon overcoat of rigid magnetic media,” Tribology Letters, vol. 4, no. 3-4, pp. 267–275, 1998.
[34]  T. Aoyagi, J. Takimoto, and M. Doi, “Molecular dynamics study of polymer melt confined between walls,” Journal of Chemical Physics, vol. 115, no. 1, pp. 552–559, 2001.
[35]  M. S. Jhon, G. Sekhon, and R. Armstrong, “The response of polymer molecules in a flow,” in Advances in Chemical Physics, I. Prigogine and S. A. Rice, Eds., vol. 66, pp. 153–211, John Wiley, New York, NY, USA, 1987.
[36]  Q. Guo, S. Izumisawa, D. M. Phillips, and M. S. Jhon, “Surface morphology and molecular conformation for ultrathin lubricant films with functional end groups,” Journal of Applied Physics, vol. 93, no. 10, pp. 8707–8709, 2003.
[37]  K. Kremer and G. S. Grest, “Dynamics of entangled linear polymer melts:? a molecular-dynamics simulation,” Journal of Chemical Physics, vol. 92, no. 8, pp. 5057–5086, 1990.
[38]  S. Izumisawa and M. S. Jhon, “Stability analysis and molecular simulation of nanoscale lubricant films with chain-end functional groups,” Journal of Applied Physics, vol. 91, no. 10, p. 7583, 2002.
[39]  S. J. Vinay, D. M. Phillips, Y. S. Lee et al., “Simulation of ultrathin lubricant films spreading over various carbon surfaces,” Journal of Applied Physics, vol. 87, no. 9, pp. 6164–6166, 2000.
[40]  X. Ma, J. Gui, L. Smoliar et al., “Spreading of perfluoropolyalkylether films on amorphous carbon surfaces,” Journal of Chemical Physics, vol. 110, no. 6, pp. 3129–3137, 1999.
[41]  Y. T. Hsia, Q. Guo, S. Izumisawa, and M. S. Jhon, “The dynamic behavior of ultrathin lubricant films,” Microsystem Technologies, vol. 11, no. 8-10, pp. 881–886, 2005.
[42]  G. W. Tyndall, R. J. Waltman, and D. J. Pocker, “Concerning the interactions between Zdol perfluoropolyether lubricant and an amorphous-nitrogenated carbon surface,” Langmuir, vol. 14, no. 26, pp. 7527–7536, 1998.
[43]  G. W. Tyndall, T. E. Karis, and M. S. Jhon, “Spreading profiles of molecularly thin perfluoropolyether films,” Tribology Transactions, vol. 42, no. 3, pp. 463–470, 1999.
[44]  K. Binder, Monte Carlo and Molecular Dynamics Simulations in Polymer Science, Oxford University Press, Oxford, UK, 1995.
[45]  Q. Guo, S. Izumisawa, M. S. Jhon, and Y. T. Hsia, “Transport properties of nanoscale lubricant films,” IEEE Transactions on Magnetics, vol. 40, no. 4, pp. 3177–3179, 2004.
[46]  P. G. de Gennes, Scaling Concepts in Polymer Physics, Cornell University Press, Ithaca, NY, USA, 1979.
[47]  X.-C. Guo, B. Knigge, B. Marchon, R. J. Waltman, M. Carter, and J. Burns, “Multidentate functionalized lubricant for ultralow head/disk spacing in a disk drive,” Journal of Applied Physics, vol. 100, no. 4, Article ID 044306, 2006.
[48]  X.-C. Guo, T. Karis, H. Deng, Q. Dai, J. Burns, and R. J. Waltman, “Fomblin multidentate lubricants for ultra-low magnetic spacing,” IEEE Transactions on Magnetics, vol. 42, no. 10, pp. 2504–2506, 2006.
[49]  H. Tani, K. Sakamoto, and N. Tagawa, “Conformation of ultrathin pfpe lubricants with different structure on magnetic disksdirect observation and MD simulation,” IEEE Transactions on Magnetics, vol. 45, no. 11, pp. 5050–5054, 2009.
[50]  R. N. Kono, S. Izumisawa, M. S. Jhon, C. A. Kim, and H. J. Choi, “Rheology of perfluoropolyether lubricants,” IEEE Transactions on Magnetics, vol. 37, no. 4 I, pp. 1827–1829, 2001.
[51]  H. J. Choi, Q. Guo, P. S. Chung, and M. S. Jhon, “Molecular rheology of perfluoropolyether lubricant via nonequilibrium molecular dynamics simulation,” IEEE Transactions on Magnetics, vol. 43, no. 2, pp. 903–905, 2007.
[52]  C. M. Mate and V. J. Novotny, “Molecular conformation and disjoining pressure of polymeric liquid films,” The Journal of Chemical Physics, vol. 94, no. 12, pp. 8420–8427, 1991.
[53]  S. Izumisawa and M. S. Jhon, “Calculation of disjoining pressure for lubricant films via molecular simulation,” IEEE Transactions on Magnetics, vol. 42, no. 10, pp. 2543–2545, 2006.
[54]  Q. Guo, The static and dynamic properties of nano-structured thin oligomeric films [Ph.D. thesis], Carnegie Mellon University, Pittsburgh, Pa, USA, 2006.
[55]  Y. I. Jhon, S. E. Zhu, J. H. Ahn, and M. S. Jhon, “The mechanical responses of tilted and non-tilted grain boundaries in graphene,” Carbon, vol. 50, no. 10, pp. 3708–3716, 2012.
[56]  W. T. Kim, D. Kim, S. H. Vemuri, S. C. Khang, P. S. Chung, and M. S. Jhon, “Multicomponent gas mixture air bearing modeling via lattice Boltzmann method,” Journal of Applied Physics, vol. 109, no. 7, Article ID 07B759, 3 pages, 2011.
[57]  H. M. Kim, J. H. Kang, and M. S. Jhon, “Hydro-kinetic approach in non-Newtonian lattice Boltzmann flow simulation,” Journal of the Korean Physical Society, vol. 58, article 444, 2011.
[58]  D. Kim, H. M. Kim, M. S. Jhon, S. J. Vinay, and J. Buchanan, “A characteristic non-reflecting boundary treatment in lattice Boltzmann method,” Chinese Physics Letters, vol. 25, no. 6, article 1964, 2008.
[59]  X. Ma, C. L. Bauer, M. S. Jhon, J. Gui, and B. Marchon, “Monte Carlo simulations of liquid spreading on a solid surface: effect of end-group functionality,” Physical Review E, vol. 60, no. 5, pp. 5795–5801, 1999.
[60]  D. M. Phillips, A. S. Khair, and M. S. Jhon, “Mathematical simulation of ultra-thin polymeric film spreading dynamics,” IEEE Transactions on Magnetics, vol. 37, no. 4 I, pp. 1866–1868, 2001.
[61]  D. M. Phillips and M. S. Jhon, “Dynamic simulation of nanoscale lubricant films,” Journal of Applied Physics, vol. 91, no. 10, p. 7577, 2002.
[62]  W. T. Kim, M. S. Jhon, Y. Zhou, I. Staroselsky, and H. Chen, “Nanoscale air bearing modeling via lattice Boltzmann method,” Journal of Applied Physics, vol. 97, no. 10, Article ID 10P304, 3 pages, 2005.
[63]  Q. Guo, L. Li, Y.-T. Hsia, and M. S. Jhon, “A spreading study of lubricant films via optical surface analyzer and molecular dynamics,” IEEE Transactions on Magnetics, vol. 42, no. 10, pp. 2528–2530, 2006.
[64]  Q. Guo, L. Li, Y.-T. Hsia, and M. S. Jhon, “Stability analysis of ultrathin lubricant films via surface energy measurements and molecular dynamics simulations,” Journal of Applied Physics, vol. 97, no. 10, Article ID 10P302, 3 pages, 2005.
[65]  H. M. Kim, D. Kim, W. T. Kim, P. S. Chung, and M. S. Jhon, “Langmuir slip model for air bearing simulation using the Lattice Boltzmann method,” IEEE Transactions on Magnetics, vol. 43, no. 6, pp. 2244–2246, 2007.

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