Skip to main content
Log in

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

  • Original Paper
  • Published:
Tribology Letters Aims and scope Submit manuscript

Abstract

Magnetic hard disks coated with ztetraol lubricant were characterized with temperature programed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Ztetraol was found to have two adsorbed states, with desorption temperatures of ~650 and ~950 K. The complete removal of the low temperature state by solvent extraction identified it as due to the mobile lubricant. Desorption of the CF3 mass fragment was observed only at high temperature, indicating that lubricant in this state was in contact with the surface, which allowed the assignment of this high temperature state to the bonded lubricant. UV irradiation was found not to alter the TPD of the unextracted lubricant film. In contrast, the TPD of the UV-bonded layer remaining after extraction was observed to have only one desorption state, stabilized at ~40 K higher temperature as compared with the naturally bonded layer. XPS of the mobile layer was accomplished using spectral subtraction of the C1s carbon overcoat peak (284.8 eV BE), and the perfluoroethylene and perfluoromethylene lubricant peaks (293.5 and 295.0 eV BE, respectively), as a function of UV exposure. No change in the mobile lubricant layer was found with increasing UV exposure. C1s XPS of the UV-bonded layer identified five surface species and assigned XPS peaks to each: the carbon overcoat peak at 284.8 eV BE, ether peak at 286.4 eV BE, organic acid peak at 288.7 eV BE, perfluoroethylene peak at 293.5 eV BE, and the perfluoromethylene peak at 295.0 eV BE. Changes in the relative intensity of the assigned peaks with increasing UV irradiation exposure time were observed. The integration of the assigned XPS peaks from the UV-bonded layer with increasing UV exposure was used to identify UV dependent changes in the bonded layer. A significant relative decrease in the perfluoromethylene lubricant component was observed with increasing exposure, with a simultaneous increase of both the ether and organic acid surface concentrations. Quantum chemical calculations using small molecular models of the ztetraol were used to elucidate the XPS and TPD observations. The calculations revealed that the lubricant is fragmented with irradiation, forming reactive end groups, a volatile CF2O, and a hydrolyzeable CFO terminated fragment all consistent with the XPS results. The mechanistic implications and the possible surface chemistry are discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

References

  1. 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)

    Article  CAS  Google Scholar 

  2. Bhushan, B.: Tribology and Mechanics of Magnetic Storage Devices, 2nd edn. Springer, New York (1996)

    Book  Google Scholar 

  3. Waltman, R.J., Tyndall, G.W., Pacansky, J.: Computer-modeling study of the interactions of Zdol with amorphous carbon surfaces. Langmuir 15, 6470–6483 (1999)

    Article  CAS  Google Scholar 

  4. Guo, X.-C., Knigge, B., Marchon, B., Waltman, R.J., Carter, M., Burns, J.: Multidentate functionalized lubricant for ultra low head/disk spacing in a disk drive. J. Appl. Phys. 100, 044306 (2006)

    Article  Google Scholar 

  5. Solvat Product Data Sheet: http://www.Solvaysolexis.com. Accessed 26 Aug 2004

  6. Sianesi, D., Zamboni, V., Fontanelli, R., Binaghi, M.: Perfluoropolyethers: their physical properties and behavior at high and low temperatures. Wear 18, 85–100 (1971)

    Article  CAS  Google Scholar 

  7. Stirniman, M.J., Falcone, S.J., Marchon, B.J.: Volatility of per-fluoropolyether lubricants measured by thermogravimetric analysis. Tribol. Lett. 6, 199–205 (1999)

    Article  CAS  Google Scholar 

  8. Lei, R.E., Gellman, A.J., Jones, P.M.: Thermal stability of fomblin z and fomblin zdol thin films on amorphous hydrogenated carbon. Tribol. Lett. 11, 1–5 (2001)

    Article  CAS  Google Scholar 

  9. Chang, T., Zhao, B., Chao, J., Meeks, S., Velidandea, V.: The lubricant migration rate on the hard disk surface. Tribol. Lett. 9(3–4), 181 (2000)

    Google Scholar 

  10. Ma, X., Gui, J., Smoliar, L., Grannen, K., Marchon, B., Jhon, M.S., Bauer, C.L.: Spreading of perfluoropolyakylether films on amorphous carbon surfaces. J. Chem. Phys. 110(No. 6), 3129 (1999)

    Article  CAS  Google Scholar 

  11. Li, L., Jones, P.M., Hsia, Y.T.: Effect of chemical structure and molecular weight on high-temperature stability of some fomblin Z-type lubricants. Tribol. Lett. 16(1–2), 21–27 (2004)

    Article  Google Scholar 

  12. Karis, T.E., Marchon, B., Flores, V., Scarpella, M.: Lubricant spin-off from magnetic recording disks. Tribol. Lett. 11(No. 3–4), 151 (2001)

    Article  CAS  Google Scholar 

  13. 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)

    Article  CAS  Google Scholar 

  14. Fong, W., Bogy, B.D.: The decomposition mechanisms of a perfluoropolyether at the head/disk interface of hard disk drives. Tribol. Lett. 5, 203–209 (1998)

    Article  Google Scholar 

  15. Bhushan, B., ChengWear, Y.: Degradation mechanisms of magnetic thin-film rigid disks with different lubricants using mass spectrometry. J. Appl. Phys. 81, 5390 (1997)

    Article  CAS  Google Scholar 

  16. Kasai, P.H.: Perfluoropolyethers: intramolecular disproportionation. Macromolecules 25, 6791–6799 (1992)

    Article  CAS  Google Scholar 

  17. Kasai, P.H., Tang, W.T., Wheeler, P.: Degradation of perfluoropolyethers catalyzed by aluminum oxide. Appl. Surf. Sci. 51, 201–211 (1991)

    Article  CAS  Google Scholar 

  18. Li, L., Jones, P.M., Merzikline, A.G., Hsia, Y.T.: Resistance of Z-type lubricants to Lewis acid-catalyzed decomposition: effect of chemical and electronic structure of end groups. Tribol. Lett. 17(4), 953–959 (2004)

    Article  CAS  Google Scholar 

  19. Reich, L., Stivala, S.S.: Elements of Polymer Degradation. McGraw-Hill Book Company, New York (1971)

    Google Scholar 

  20. Wu, J., Mate, C.M.: Contact angle measurements of lubricated silicon wafers and hydrogenated carbon overcoats. Langmuir 14, 4929–4934 (1998)

    Article  CAS  Google Scholar 

  21. Dagastine, R.R., White, L.R., Jones, P.M., Hsia, Y.-T.: Effect of van der Waals forces on molecularly thin lubricant in the magnetic storage head-disk interface. J. Appl. Phys. 98, 124906 (2005)

    Article  Google Scholar 

  22. Chen, H., Li, L., Merzlikine, A.G., Hsia, Y.T., Jhon, M.S.: Surface energy and adhesion of perfluoropolyether nanofilms on carbon overcoat: the end group and backbone chain effect. J. Appl. Phys. 99, 08N103 (2006)

    Article  Google Scholar 

  23. Vurens, G.H., Gudeman, C.S., Lin, L.J., Foster, J.S.: Mechanism of ultraviolet and electron bonding of perfluoropolyethers. Langmuir 8, 1165–1169 (1992)

    Article  CAS  Google Scholar 

  24. Vurens, G.H., Gudeman, C.S., Lin, L.J., Foster, J.S.: The mechanism of ultraviolet bonding of perfluoropolyether lubricant [used in magnetic recording]. IEEE Trans. Magn. 29(1), 282 (1993)

    Article  CAS  Google Scholar 

  25. Guo, X.C., Waltman, R.J.: Mechanism of ultraviolet bonding of perfluoropolyethers revisited. Langmuir 23, 4293 (2007)

    Article  CAS  Google Scholar 

  26. Diaz, J., Paolicelli, G., Ferrer, S., Comin, F.: Separation of the sp3 and sp2 components in the C1s photoemission spectra of amorphous carbon films. Phys. Rev. B 54(11), 8064 (1996)

    Article  CAS  Google Scholar 

  27. Delley, B.J.: An all-electron numerical method for solving the local density functional for polyatomic molecules. J. Chem. Phys. 92, 508–517 (1990)

    Article  CAS  Google Scholar 

  28. Delley, B: A standard tool for density functional calculations: review and advances. In: Seminario, J.M., Politzer, P. (eds.) Modern Density Functional Theory, vol. 2. Elsevier Science B, New York (1995)

  29. Lee, C., Yang, Y., Parr, R.G.: Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 37, 785 (1988)

    Article  CAS  Google Scholar 

  30. Becke, A.D.: Density-functional exchange-energy approximation with correct asymptotic behavior. Phys. Rev. A 38, 30989 (1988)

    Article  Google Scholar 

  31. Perdew, J.P., Wang, Y.: Accurate, simple analytic representation of the electron–gas correlation energy. Phys. Rev. B 45, 13244 (1992)

    Article  Google Scholar 

  32. Fan, L., Ziegler, T.: Nonlocal density functional theory as a practical tool in calculations on transition states and activation energies. Applications to elementary reaction steps in organic chemistry. J. Am. Chem. Soc. 114, 10890–10897 (1992)

    Article  CAS  Google Scholar 

  33. Broyden, C.G.: The convergence of a class of double-rank minimization algorithms. J. Inst. Math. Appl. 6, 76–90 (1970)

    Article  Google Scholar 

  34. Fletcher, R.: A new approach to variable metric algorithms. Comput. J. 13, 317–322 (1970)

    Article  Google Scholar 

  35. Goldfarb, D.: A family of variable metric updates derived by variational means. Math. Comput. 24, 23–26 (1970)

    Article  Google Scholar 

  36. Shanno, D.F.: Conditioning of Quasi-Newton methods for function minimization, July (1970). Math. Comput. 24, 647 (1970)

    Article  Google Scholar 

  37. Toney, M.F., Mate, C.M., Leach, K.A., Pocker, D.: Thickness measurements of thin perfluoropolyether films on silicon and amorphous-hydrogenated carbon with X-ray reflectivity, ESCA and ellipsometry. J. Coll. Interface Sci. 225, 219–226 (2000)

    Article  CAS  Google Scholar 

  38. Bottino, F.A., Pasquale, G.D., Pollocono, A., Pilati, F., Toselli, M., Tonelli, C.: XPS study on surface segregation in poly(ethylene-iso/terephthalate)-perfluoropolyether block copolymers. Macromolecules 31, 7814–7819 (1998)

    Article  CAS  Google Scholar 

  39. Karis, T.E.: Tribochemistry in contact recording. Tribol. Lett. 10(3), 149 (2001)

    Article  CAS  Google Scholar 

  40. Paserba, K.R., Gellman, A.J.: Desorption kinetics and energetics of monodisperse fomblin zdol from carbon surfaces. J. Phys. Chem. B 105, 12105–12110 (2001)

    Article  CAS  Google Scholar 

  41. Rivera, P.J., Hirtzel, C.S.: Temperature programed desorption of molecules from solid surfaces: effects of surface site distribution and lateral interactions on desorption spectra. Chem. Eng. Commun. 108, 333–346 (1991)

    Article  CAS  Google Scholar 

  42. Pacansky, J., Waltman, R.J.: Electron beam irradiation of perfluoropolyethers: experimental analysis of main-chain degradation. Chem. Mater. 5, 486–494 (1993)

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Paul M. Jones.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Jones, P.M., Merzikline, A., Yan, X. et al. 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, 201 (2011). https://doi.org/10.1007/s11249-011-9838-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11249-011-9838-y

Keywords

Navigation