Annalen der Physik

Advances in physics

The pulsed laser deposition is a new technique for the growth of thin films,which has been attended generally by people recently The physical principle, unique characteristics and the proceeding of the study were introduced briefly In addation, the result of the PtSi nanometer thin film based on silicon prepared by the pulsed laser deposition was describedPULS

Pulsed laser deposition of thin films

http://milad-engc.persiangig.com/Recent.pdf

Recent research advances on the dynamic analysis of composite shells: 2000-2009

The impact-induced deposition of Al13 clusters with icosahedral structure on Ni(0 0 1) surface was studied by molecular dynamics (MD) simulation using Finnis–Sinclair potentials. The incident kinetic energy (Ein) ranged from 0.01 to 30 eV per atom. The structural and dynamical properties of Al clusters on Ni surfaces were found to be strongly dependent on the impact energy. At much lower energy, the Al cluster deposited on the surface as a bulk molecule. However, the original icosahedral structure was transformed to the fcc-like one due to the interaction and the structure mismatch between the Al cluster and Ni surface. With increasing the impinging energy, the cluster was deformed severely when it contacted the substrate, and then broken up due to dense collision cascade. The cluster atoms spread on the surface at last. When the impact energy was higher than 11 eV, the defects, such as Al substitutions and Ni ejections, were observed. The simulation indicated that there exists an optimum energy range, which is suitable for Al epitaxial growth in layer by layer. In addition, at higher impinging energy, the atomic exchange between Al and Ni atoms will be favourable to surface alloying.

Nuclear instruments and methods in physics research section B : beam interactions with materials and atoms

Phase change materials are probably the most promising candidates to be used in the upcoming generation of memory technologies. One of the main challenges for applications is the resistance increase over time occurring in the amorphous state called resistance drift. We have studied the time and temperature dependence of resistance drift in thin films of GeTe and other phase change materials. A relationship for the time and temperature dependence of the activation energy for conduction is used to describe resistance drift. Photothermal Deflection Spectroscopy shows that the optical band gap is increasing, suggesting to be the reason for an increase of the activation energy. Furthermore, our results on various materials show that the magnitude of drift tends to be dependent on the activation energy for conduction. A similar trend is observed for the dependence of the threshold switching field on the optical band gap.

Impact of DoS changes on resistance drift and threshold switching in amorphous phase change materials

Experimental and numerical study on the modal characteristics of hybrid carbon fiber composite foam filled corrugated sandwich cylindrical panels

Disturbance rejection control for vibration suppression of piezoelectric laminated thin-walled structures

Geometrically nonlinear static FE-simulation of multilayered magneto-electro-elastic composite structures

A geometrically nonlinear large rotation shell theory is proposed for dynamic finite element (FE) analysis of piezoelectric integrated thin-walled smart structures. The large rotation theory, which has six independent kinematic parameters but expressed by five nodal degrees of freedom (DOFs), is based on first-order shear deformation (FOSD) hypothesis. The two-dimensional (2D) FE model is constructed using eight-node quadrilateral shell elements with five mechanical DOFs per node and one electrical DOF per piezoelectric material layer with linear constitutive equations. The linear and nonlinear dynamic responses are determined by the central difference algorithm (CDA) and the Newmark method. The results are compared with those obtained by simplified nonlinear theories, as well as those reported in the literature. It is shown that the present large rotation theory yields considerable improvement if the structures undergo large displacements and rotations.

https://iopscience.iop.org/article/10.1088/0964-1726/22/10/105025/pdf

Rüdiger Schmidt

Papers

Impact of DoS changes on resistance drift and threshold switching in amorphous phase change materials

Experimental and numerical study on the modal characteristics of hybrid carbon fiber composite foam filled corrugated sandwich cylindrical panels

Disturbance rejection control for vibration suppression of piezoelectric laminated thin-walled structures

Geometrically nonlinear static FE-simulation of multilayered magneto-electro-elastic composite structures

Large rotation FE transient analysis of piezolaminated thin-walled smart structures