Universal critical-like scaling of dynamics in plastic crystals

• Published in: Journal of non-crystalline solids 2011-01, Vol.357 (2), p.329-333
• Main Authors: Martínez-García, J.C., Tamarit, J.Ll, Rzoska, S.J., Drozd-Rzoska, A., Pardo, L.C., Barrio, M.
• Format: Article
• Language: English
• Subjects: Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: structure, mechanical and thermal properties; Cristalls mixtos; Cristalls plàstics; Cross-disciplinary physics: materials science; rheology; Diffusion in solids; Distributed memory; Dynamics; Enginyeria dels materials; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Glass transition; Glass transition temperature; Glass transitions; Glasses (including metallic glasses); Materials plàstics i polímers; Materials science; Mixed crystals; Molecular dynamics; Orientationally disordered crystals; Phase transformations; Physics; Plastic crystals; Relaxation time; Specific materials; Specific phase transitions; Structural relaxation; Transformations; Transport properties of condensed matter (nonelectronic); Treatment of materials and its effects on microstructure and properties; Vitrification; Walking; Àrees temàtiques de la UPC
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2010.06.065

Many theoretical models for the glassy dynamics have been proposed so far describing the changes in molecular dynamics along the extraordinary slowing down in the vitrification process of a disordered phase on cooling. Many of these theories share the concept of cooperative rearranging regions firstly proposed by Adam and Gibbs. Among them, the dynamical scaling model (DSM) is based on the random diffusion of free volume which creates random walking clusters formed by cooperatively rearranging entities. Within this framework a critical phenomenon relating a hidden phase transition at T C (below T g ) implies the divergence of the relaxation time ( τ) or viscosity ( η) τ, η ∝ ( T − T C ) − ϕ with a universal scaling exponent φ → 9. In this work we apply the DSM model to orientational glasses, obtained from the quenching of orientationally disordered phases (plastic crystals) via the application of the linearized derivative-based transformation of dielectric spectroscopy τ( T) data.