Year-end Sale % OFF 
Abstract
Intrinsic differences between tunneling two-level systems (TLSs) in molecular versus polymeric glasses are revealed by studying the effect of compression on TLS dynamics. Photon echo studies under variable low-temperature (1.1-2.3 K) and high-pressure (0-30 kbar) conditions have been performed to contrast the effect of compression on molecular [2-methyl-tetrahydrofuran (2MTHF)] versus polymer [Polymethylmethacrylate (PMMA)] glasses. The pressure-induced reduction in the magnitude of the optical dephasing rate of rhodamine 640 in a molecular glass (2MTHF) is found to be comparable to the volume decrease of the glass (e.g., approximately 20% at 30 kbar), indicating that TLSs in 2MTHF are associated with void space or low-density regions of the glass. In contrast, the relative pressure insensitivity observed for organic polymer glasses (PMMA) supports the idea that these TLSs are associated with side chain defects. The power-law exponent for the temperature-dependent dephasing in 2MTHF also decreased significantly at high pressure, suggesting a change in the form of the TLS density of states upon compression of the molecular glass.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
