Spin–lattice relaxation mechanisms in the smectic phases of TBBA

The observed frequency dispersions of the proton spin–lattice relaxation rate T−11 in the smectic phases of TBBA in the 105–108 Hz region have been analyzed in terms of the order fluctuation, self‐diffusion, and rotational contributions to T−11. In the smectic A and smectic C phases the main rate determining contributions are order fluctuations and fast self‐diffusion, whereas in the smectic H and smectic VI phases fast rotations and slow translation self‐diffusion determine T−11.