Hysteresis effects and mesoscopic domains: Precursors for the formation of orientational glass states
Institut für Physikalische Chemie, Johannes Gutenberg-Universität, 55099 Mainz, Germany
Accepted: 10 August 1998
single crystals were investigated using proton NMR for 0.8 < x < 1. They undergo a first-order transition from the orientationally disordered high-temperature α-phase into the low-temperature β-phase. This transition exhibits a thermal hysteresis which strongly increases upon lowering x. In the coexistence range evidence for nanoscopic domains was obtained using proton spin diffusion. The characteristic dimensions of the domains decrease as the critical concentration xc is approached, below which an orientational glass state is stable at low temperature. This observation indicates that close to xc the orientational glasses are to be characterized as nano domain states.
PACS: 64.70.Pf – Glass transitions / 77.22.Ch – Permittivity (dielectric function)
© EDP Sciences, 1998