Journal Article

FZJ-2023-03273

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Atomic-Resolution Mapping of Localized Phonon Modes at Grain Boundaries

Haas, B. (Corresponding author)Extern* ; Boland, T. M.Extern* ; Elsässer, C.Extern* ; Singh, A. K.Extern* ; March, K.Extern* ; Barthel, J.FZJ* ; Koch, C. T.Extern* ; Rez, P.Extern*

2023
ACS Publ. Washington, DC

This record in other databases:      

Please use a persistent id in citations: doi:10.1021/acs.nanolett.3c01089  doi:10.34734/FZJ-2023-03273

Abstract: Phonon scattering at grain boundaries (GBs) is significant in controlling the nanoscale device thermal conductivity. However, GBs could also act as waveguides for selected modes. To measure localized GB phonon modes, milli-electron volt (meV) energy resolution is needed with subnanometer spatial resolution. Using monochromated electron energy loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) we have mapped the 60 meV optic mode across GBs in silicon at atomic resolution and compared it to calculated phonon densities of states (DOS). The intensity is strongly reduced at GBs characterized by the presence of 5- and 7-fold rings where bond angles differ from the bulk. The excellent agreement between theory and experiment strongly supports the existence of localized phonon modes and thus of GBs acting as waveguides.

---

Contributing Institute(s):

1. Materialwissenschaft u. Werkstofftechnik (ER-C-2)

Research Program(s):

1. 5353 - Understanding the Structural and Functional Behavior of Solid State Systems (POF4-535) (POF4-535)

Appears in the scientific report 2023

---

Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 10 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---