The spinhyphen;lattice relaxation time (T1) and the transverse relaxation time (T2) are determined, by the spinecho nuclear magnetic resonance method, for the isotropichyphen;liquid state of the liquidhyphen;crystal compoundsphyphen;azoxyanisole (PAA), cholesteryl benzoate, cholesterylnhyphen;butyrate, and cholesteryl propionate. TheT1values are 1.2 sec for PAA, and 0.06 to 0.15 sec for the cholesteryl compounds. TheT2values are 0.02 to 0.03 sec for the cholesteryl compounds, and at least 0.05 sec for PAA. The results are consistent with those for other isotropic liquids. As the temperature decreases toward the transition to the anisotropic phase, a pretransitional decrease ofT2is observed for the cholesteryl compounds, and a similar decrease ofT1for PAA. An explanation in terms of Frenkel's theory of heterophase fluctuations is discussed. Thermal expansion curves and interphase surface tension for PAA are also considered, and hysteresishyphen;like behavior of the phase transition.
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