مجله فیزیک کاربردی
سال ششم شماره 1 (پیاپی 10، بهار و تابستان 1395)

In the present work, gold thin films growth process using the evaporation method has been simulated. For this purpose, the COMSOL Multiphysics 5.0 simulator software was used. Three-dimensional models were constructed and geometry, mesh analysis, boundary conditions and related relations were defined and studied. Film thickness, density, heat flux and other related parameter to deposition were investigated. Using planar regression, surface equation of the gold thin films was calculated and the effect of the temperature of gold source on thickness of films was investigated. Results showed that there is a correlation between the temperature of source and the thickness of gold films. Using non-linear regression, a model was represented in order to describe the dependency of film thickness on source temperature. Comparing the simulation results in this paper for thickness and curvature of gold thin films with expected behavior distribution on substrate, a promising accommodation between the simulated data and this trend was observed.

Acoustic wave’s applications in material structure science studies are very important. Therefore investigation of acoustic wave quality and analyzing of wave propagation and discovering of its relation with martial features has been in great interest for many scientists. Investigation of dynamic properties of porous media and studying of its relationship with static properties has very practical benefits for nondestructive methods in material science. At first the fractures are generated in two dimensional porous medium as a defect’s structures, then propagation of the acoustic waves is studied in simulated samples. We use explicit finite difference (FD) method to solve problem numerically. The results suggest some relationships between wave's dynamic properties and the effects of size and geometry of fractures or defects. The relationships of all the quantities of interest depend on the fractures direction or anisotropic effects. We also study the anisotropic effects on some practical dynamical properties of acoustic wave front. The results suggest some relations between them. The results of this simulation compare with some results that is obtained from different practical and simulation methods.

In this study, the nonlinear optical properties of a nematic liquid crystal doped with an azo dye were investigated. The magnitude and the sign refractive index and nonlinear absorption coefficient of a nematic liquid crystal doped with disperse-red-2- azo dye were measured by Z-scan techniques. The measurements were performed at 532 nm using a continues wave (CW) Nd: Yag laser.
We were looking for the effect of initial alignment on the nonlinearity of azo doped nematic liquid crystals (NLCs). The nonlinear refractive index and nonlinear absorption coefficient of homogeneous alignment sample is obtained in the order of 10-6 cm2/W and 10-1 cm/W, respectively with negative sign. The nonlinear refractive index and nonlinear absorption coefficient of homeotropic alignment sample is obtained in the order of 10-9 cm2/W and 10-5 cm/W, respectively with positive sign. Comparison of Z-san results shows the magnitudes of nonlinearity in homogeneous alignment samples are larger than homeotropic ones.

In this paper a model with anisotropic pressures for dark matter halo is assumed. The corresponding metric matches the schwarzchild metric at the surface of halo. Then the energy conditions, rotation curve and gravitational lensing effect are investigated.

In this paper,the structural properties(such as lattice constant,bulk modulus,compressibility,...)of cubic phase were theoretically investigated.The calculations have been performed using a Full Potential Linearized Augmented Plane wave (FP-LAPW) method in the framework of density functional theory(DFT) with various Approximations using Wien2k package.The obtained results show that using GGA96 with spin effects is in a better agreement with other theoretical approximations.Besides,density of electronic states has beenstudied in cubic .The results show that,there is a strong covalent band between O-O,Cr-Oand La-O.These results are in good agreement with the published theoretical and experimental data.
d in cubic .The results show that,there is a strong covalent band between O-O,Cr-Oand La-O.These results are in good agreement with the published theoretical and experimental data. d in cubic .The results show that,there is a strong covalent band between O-O,Cr-Oand La-O.These results are in good agreement with the published theoretical and experimental data. d in cubic .The results show that,there is a strong covalent band between O-O,Cr-Oand La-O.These results are in good agreement with the published theoretical and experimental data.

Based on shell model , isotopes of oxygen 19 and oxygen 21 , ends to1 d 5 / 2 . Considering oxygen 16 , as a core , ( Core with shell closed ) , the nucleus of outside the closed shell , we , can be considered a Three - particle , and Five - particle . Since , the capacity nucleons , are effective in the energy spectrum of in oxygen 19 and oxygen 21 isotopes . In this work , we use the shell model , And considering the Gaussian potential , for interaction between nucleons , to calculate the energy levels , these isotopes , we , Considering the Schrödinger equation , and use of the analysis super symmetry method, The results of our calculations , are compared with , experimental results , and the results of other research groups , is a good agreement .

Organic light-emitting diodes (OLED), which are fabricated based on organic materials, are a new class of lighting sources with many advantage in comparison to common light-emitting diodes. One of these promising depictions of OLEDs is their capability for fabrication of transparent displays in which the device possesses a transparency up to 70% during the off-state. In these types of displays, all the components such as substrate, the anode, the organic-polymer layers, and the cathode electrode are transparent and the emission can leave the device from the both sides. Recently, transparent OLEDs have attracted a lot of attention due to their exceptional applications such as transparent flat-panel displays, car front windows, and smart windows.The aim of the present research is to fabrication a transparent cathode composing of Ca , Ag by constant thickness of 20 nm and 10 nm and ZnS Dielectric coating layer with different thickness of 20,25,30,40 nm for used in the transparent organic light emitting diodes. The experimental ZnS thickness are obtained to be 25 nm. Optical transparency of 85% and low reflection of 10.50% in visible region and low surface electrical resistance of 8.6 ohm/square in Ca(20nm)/Ag(10nm)/ZnS (25nm) structure is obtained which seem to be applicable in transparent oleds