MOLECULAR ORIENTATIONAL ORDER IN THE MESOPHASES OF TBBA - RESULTS OF A CONSISTENT ANALYSIS OF NEUTRON, NQR AND NMR DATA

Incoherent neutron quasi-elastic scattering (NQES), **1**4Q nuclear quadrupole resonance (NQR) and deuterium nuclear magnetic resonance (DMR) data in the smectic VI, smectic H, smectic C, smectic A and nematic phases of terephtal-bis-butyl-aniline (TBBA) are analyzed consistently in terms of simple rotational models allowing both orientational order around the long molecular axis and fluctuations of this axis. The results seem to rule out definitely the Meyer-MacMillan and Meyer theories for the tilted phases of TBBA.