The 129Xe NMR shielding and diffusion of xenon dissolved in the chiral liquid-crystal 1-methylheptyl 4‘-(4-n-decyloxybenzoyloxy)biphenyl-4-carboxylate (10B1M7) were studied over the temperature range covering
the isotropic (I), smectic A (SmA), and ferroelectric, ferrielectric, and antiferroelectric smectic C*(SmC*)
phases. The 129Xe shielding reveals clearly the I−SmA and SmA−SmC*(ferroelectric) phase transitions. The
SmC* sub-phase transitions can also be detected by smaller but distinguishable shifts of the shielding
accompanied by line width changes. A theoretical model developed earlier is applied to the shielding data,
confirming a negative anisotropic contribution to the shielding as the SmA phase forms and allowing the
evaluation of the tilt angle in the SmC*. Diffusion experiments were mostly performed in the direction parallel
to the layer normal, i.e., along the external magnetic field, D
∥, in the smectic phases but a few experiments
were carried out in the in-plane direction, i.e., perpendicular to the external magnetic field, D
⊥, as well.
These experiments indicate large anisotropy, D
⊥/D
∥, of the 129Xe diffusion tensor that increases as the
temperature decreases. Application of the Arrhenius equation to the temperature-dependence of D
∥ reveals
different activation energies for each studied phase. This can be correlated to changes in the smectic layer
structure that occur between the different smectic phases.