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Trinkaus H.,Institute of Bio and Nanosystems IBN 1 | Buca D.,Institute of Bio and Nanosystems IBN 1 | Hollander B.,Institute of Bio and Nanosystems IBN 1 | Minamisawa R.A.,Institute of Bio and Nanosystems IBN 1 | And 2 more authors.
Journal of Applied Physics | Year: 2010

A powerful method for analyzing general strain states in layer systems is the measurement of changes in the ion channeling directions. We present a systematic derivation and compilation of the required relations between the strain induced angle changes and the components of the strain tensor for general crystalline layer systems of reduced symmetry compared to the basic (cubic) crystal. It is shown that, for the evaluation of channeling measurements, virtually all layers of interest may be described as being "pseudo- orthorhombic." The commonly assumed boundary conditions and the effects of surface misorientations on them are discussed. Asymmetric strain relaxation in layers of reduced symmetry is attributed to a restriction in the slip system of the dislocations inducing it. The results are applied to {110}SiGe/Si layer systems. © 2010 American Institute of Physics.

Sofer Z.,Institute of Chemical Technology Prague | Sedmidubsk D.,Institute of Chemical Technology Prague | Huber S.,Institute of Chemical Technology Prague | Huber S.,ASCR Institute of Physics Prague | And 5 more authors.
Journal of Crystal Growth | Year: 2011

ZnO crystals doped with Cr, Mn, Fe and Co were grown by the flux method. The prepared crystals revealed no phase separation detectable by X-ray diffraction. Structure properties were characterized by Raman and photoluminescence spectroscopy. For ZnO:Co, Mn and Cr, no spontaneous ferromagnetic moment was observed up to T=2 K whereas for the ZnO:Fe crystals the m(H) curves suggest the existence of 5 nm superparamagnetic iron clusters. At low temperatures the m(H) curves can be interpreted as a superposition of major paramagnetic and minor antiferromagnetic contribution. The paramagnetic part corresponds to the presence of Co 2, Fe 3, Mn 2 ions and small Cr atom clusters. © 2010 Published by Elsevier B.V. All rights reserved.

Singh R.,Indian Institute of Technology Delhi | Singh R.,Max Planck Institute of Microstructure Physics | Scholz R.,Max Planck Institute of Microstructure Physics | Christiansen S.,Max Planck Institute of Microstructure Physics | And 3 more authors.
Semiconductor Science and Technology | Year: 2011

The blistering phenomenon in hydrogen implanted and annealed Si 0.70Ge 0.30(0 0 1) layers was investigated. The implantation was performed with 240 keV H 2 + ions with a fluence of 5 × 10 16 cm -2. The blistering kinetics of H-implanted Si 0.70Ge 0.30 showed two different activation energies: about 1.60 eV in the lower temperature regime (350-425 °C) and 0.40 eV in the higher temperature regime (425-700 °C). Microstructural characterization of the implantation damage in SiGe layers using transmission electron microscopy revealed a damage band extending between 900 and 1200 nm below the surface. It was observed that after post-implantation annealing, a number of platelets and microcracks were formed within the damage band. These extended defects are predominantly oriented parallel to the surface, i.e. in the (0 0 1) plane. However, the extended defects oriented along the {1 1 1} planes were also observed and the density of these defects was the highest toward the end of the damage band. These experimental observations are compared with similar investigations in Si and Ge performed earlier and a plausible explanation for the blistering results in Si 0.70Ge 0.30 is presented in this work. © 2011 IOP Publishing Ltd.

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