dc.contributor.author | Shalini, Ashawaraya | |
dc.contributor.author | Liu, Y. | |
dc.contributor.author | Al-Jarah, Uday Ali Sabeeh | |
dc.contributor.author | Srivastava, G.P. | |
dc.contributor.author | Wright, C. David | |
dc.contributor.author | Katmis, F. | |
dc.contributor.author | Braun, W. | |
dc.contributor.author | Hicken, R.J. | |
dc.date.accessioned | 2013-12-02T11:19:22Z | |
dc.date.issued | 2013-10-16 | |
dc.description.abstract | The phonon spectrum of Ge2Sb2Te5 is a signature of its crystallographic structure and underlies the phase transition process used in memory applications. Epitaxial materials allow coherent optical phonons to be studied in femtosecond anisotropic reflectance measurements. A dominant phonon mode with frequency of 3.4 THz has been observed in epitaxial Ge2Sb2Te5 grown on GaSb(001). The dependence of signal strength upon pump and probe polarization is described by a theory of transient stimulated Raman scattering that accounts for the symmetry of the crystallographic structure through use of the Raman tensor. The 3.4 THz mode has the character of the 3 dimensional T2 mode expected for the Oh point group, confirming that the underlying crystallographic structure is cubic. New modes are observed in both Ge2Sb2Te5 and GaSb after application of large pump fluences, and are interpreted as 1 and 2 dimensional modes associated with segregation of Sb. | en_GB |
dc.description.sponsorship | The authors gratefully acknowledge financial support from Engineering and Physical Sciences Research Council grant EP/F015046/1 | en_GB |
dc.identifier.citation | Vol. 3, article 2965 | en_GB |
dc.identifier.doi | 10.1038/srep02965 | |
dc.identifier.grantnumber | Engineering and Physical Sciences Research Council grant EP/F015046/1 | en_GB |
dc.identifier.uri | http://hdl.handle.net/10871/14108 | |
dc.language.iso | en_US | en_GB |
dc.publisher | Nature Publishing Group | en_GB |
dc.relation.url | http://www.ncbi.nlm.nih.gov/pubmed/24129388 | en_GB |
dc.relation.url | http://hdl.handle.net/10871/13760 | |
dc.rights | Open access. This work is licensed under a Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/ | |
dc.subject | Materials science | en_GB |
dc.subject | Optical data storage | en_GB |
dc.subject | Applied physics | en_GB |
dc.subject | Optical physics | en_GB |
dc.title | Observation of T2-like coherent optical phonons in epitaxial Ge2Sb2Te5/GaSb(001) films (journal article) | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2013-12-02T11:19:22Z | |
exeter.place-of-publication | England | |
dc.description | The dataset associated with this article is in ORE at http://hdl.handle.net/10871/13760 | |
dc.identifier.eissn | 2045-2322 | |
dc.identifier.journal | Scientific Reports | en_GB |