1. Structural investigations of Ge nanoparticles embedded in an amorphous SiO2 matrix
- Author
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V. Iancu, A. Slav, Valentin S. Teodorescu, George E. Stan, Ruxandra M. Costescu, T. Stoica, Nicoleta G. Gheorghe, Magdalena Lidia Ciurea, Cristian M. Teodorescu, G. Iordache, Dan Marcov, Ana-Maria Lepadatu, and Ionel Stavarache
- Subjects
Materials science ,Analytical chemistry ,Nanoparticle ,Bioengineering ,General Chemistry ,Sputter deposition ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Amorphous solid ,Tetragonal crystal system ,X-ray photoelectron spectroscopy ,Transmission electron microscopy ,Modeling and Simulation ,General Materials Science ,Thin film ,Sol-gel - Abstract
Transmission electron microscopy and X-ray photoelectron spectroscopy analyses are performed to investigate Ge nanoparticles embedded in an amorphous SiO2 matrix. GeSiO thin films are prepared by two methods, sol–gel and radio frequency magnetron sputtering. After the deposition, the sol–gel films are annealed in either N2 (at 1 atm and 800 °C) or H2 (at 2 atm and 500 °C), and the sputtered films in H2 (at 2 atm and 500 °C), to allow Ge segregation. Amorphous Ge-rich nanoparticles (3–7 nm size) are observed in sol–gel films. Crystalline Ge nanoparticles in the high pressure tetragonal phase (10–50 nm size) are identified in the sputtered films. The size of the nanoparticles increases with Ge concentration in the volume of the film. At the film surface, the Ge concentration is much larger that in the volume for both sol–gel and sputtered films. At the same time, at the film surface, only oxidized Ge is observed.
- Published
- 2010