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Raman scattering studies in two kinds of Ge nanosystems under hydrostatic pressure
Author(s) -
Teo K. L.,
Shen Z. X.,
Liu L.,
Kolobov A. V.,
Maeda Y.
Publication year - 2004
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200405210
Subject(s) - raman scattering , substrate (aquarium) , raman spectroscopy , hydrostatic pressure , quartz , materials science , matrix (chemical analysis) , compressibility , delamination (geology) , scattering , hydrostatic equilibrium , composite material , optics , thermodynamics , geology , paleontology , oceanography , physics , subduction , tectonics , quantum mechanics
Abstract We report Raman scattering of Ge nanocrystals (NCs) embedded in SiO 2 matrix on Si substrate (Ge/SiO 2 /Si) and on quartz substrate (Ge/SiO 2 /quartz) under hydrostatic pressure. The pressure coefficient obtained for the Ge mode in the Ge/SiO 2 /quartz nanosystem is found to be almost twice as large com‐ pared with its corresponding bulk value. We explained our results using a simple elastic model, which describes the effective pressure transmitted from the matrix to the NCs. In Ge/SiO 2 /Si nanosystem, delamination of the SiO 2 film from the Si substrate occurs at ∼23 kbar due to the large difference between the compressibility of the SiO 2 matrix and Si substrate. The observed effect can be understood by the nonhomogeneous distribution of the elastic field in the Ge/SiO 2 /Si nanosystem using a finite element analysis. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)