Deuteron and carbon magnetic resonance studies of supercooled liquid and glassy salol

The glass-former salol was studied using carbon and deuteron NMR. For the C -13 measurements protonated samples were used. For the deuteron experiments salol was selectively deuterated at the phenyl ring. The measurement of th e spin-lattice relaxation times provides clear evidence for an anisotropic reorientation of the molecules in the supercooled liquid. Close to the glas s transition a bimodal longitudinal magnetization recovery is observed whic h indicates the presence of relatively slow intramolecular degrees of freed om. From deuteron solid echo spectra this process is identified as a uniaxi al large amplitude motion of the phenyl group which exhibits a broad distri bution of correlation times. (C) 2000 American Institute of Physics. [S0021 -9606(00)51213-6].