Zeitschrift für Physik B Condensed Matter

, Volume 78, Issue 2, pp 235–240 | Cite as

Proton magnetic relaxation studies of molecular diffusion in the liquid crystal 40.5

  • G. Ravindranath
  • K. Venu
  • V. S. S. Sastry


Nuclear magnetic relaxation spectroscopy is used to study the molecular dynamics in a liquid crystal butoxy benzylidene pentylaniline (40.5) in the frequency range 4 to 30 MHz and the results are compared with two other members of the same homologous series (viz 40.8 and 40.6). Spin lattice relaxation time studies indicate that molecular self diffusion (SD) and reorientation processes (R) dominate the relaxation process and their relative contributions are quantified. This contrasts with the case where order director fluctuations (ODF) effectively mediate relaxation process and all the three processes are found to be important in 40.6 in a similar frequency range.T1D in 40.5 in the nematic phase shows temperature dependence indicating that ODF that is present at low frequencies might be diffusion assisted. These relaxation data are analysed in theS B phase of this compound also to obtain contributions to the relaxation process. These results are also analysed to obtain different parameters associated with the above dynamical processes.


Liquid Crystal Relaxation Process Molecular Diffusion Spin Lattice Relaxation Lattice Relaxation 
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Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • G. Ravindranath
    • 1
  • K. Venu
    • 1
  • V. S. S. Sastry
    • 1
  1. 1.School of PhysicsUniversity of HyderabadHyderabadIndia

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