Central peaks in (NH4I)x(KI)1−x

Abstract Quasielastic measurements are reported on (NH 4 I) x (KI) 1− x . This mixed molecular system reveals a variety of structural phases and different glass states. Close to the structural phase transition, in constant Q -scans through the reciprocal lattice points at which superstructure reflections appear in the orientationally ordered phase, two central peaks were detected.