Dynamic heterogeneity in the glass-like monoclinic phases of some halogen methane compounds

M. J. ZURIAGA; S.C. PEREZ; L.C.PARDO; J.LL. TAMARIT

AIP CONFERENCE PROCEEDINGS

American Institute of Physics.

Año: 2013 vol. 1518 p. 59 - 66

0094-243X

In this work we study the heterogeneity of the dynamics on the low-temperature monoclinic phases of the simple molecular glassy systems CBrnCl4-n, n = 0, 1, 2. In these systems the disorder comes exclusively from reorientational jumps mainly around the C3 molecular axes. The different time scales are determined by means of the analysis of the spin-lattice relaxation time obtained through Nuclear Quadrupole Resonance (NQR) technique. Results are compared with those obtained from dielectric spectroscopy, from which two  and relaxation times appear. NQR results enable us to ascribe with no doubt that the existence of two relaxations is due to dynamical heterogeneities which are the consequence of the different molecular surroundings of the molecules in the asymmetric unit cell of systems here studied.