The study of the structural and thermodynamic properties of
two-dimensional fluid with disc-shape molecules by Lenard-Jones potential model
Seyed-Fardin
Taghizadeh
عضو هیأت علمی دانشگاه یاسوج
author
Sakineh
Ghanbari
دانش آموخته کارشناسی ارشد دانشگاه یاسوج
author
Zohreh
Sazeshi
دانش آموخته کارشناسی ارشد
author
text
article
2012
per
In this paper, by considering Lenard-Jones potential between disc-shape molecules, the radial distribution function, the direct correlation function and the structure factor are calculated by using compressibility and Ornstein-Zernike equations. In addition, the pressure and compressibility equations for this potential are calculated. Results show that for the L. J. potential, the radial distribution function does not approach zero in molecule's diameter range.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
2
v.
3
no.
2012
1
7
http://jrmbs.scu.ac.ir/article_10438_8bc1350b190f3486d05027723b6c6274.pdf
Calculation of orientation distribution functions in hard ellipsoid and Gay- Berne liquid crystals from order parameters
Abol Ghasem
Avazpour
عضو هیأت علمی دانشگاه یاسوج
author
Seyedeh Mahboubeh
Hekmatzadeh
دانش آموخته کارشناسی ارشد دانشگاه یاسوج
author
Ebrahim
Sadeghi
عضو هیأت علمی دانشگاه یاسوج
author
Shaker
Hajati
دانش اموخته کارشناسی ارشد دانشگاه یاسوج
author
text
article
2012
per
The most fundamental characteristic of liquid crystals, at least from a microscopic point of view, is the presence of long-range orientational order while the positional order is limited or absent. We introduce distribution functions which can help us in calculating order parameters and other relevant averages. The singlet and pair distributions are discussed. Equations for the relevant thermodynamic observables in terms of these distributions are given. Also, we introduce order parameters by expanding the singlet distribution in a complete basis set. The effect of molecular symmetry on the orientational order parameters is examined. Using the known order parameters, the orientation distribution function of hard ellipsoid and the Gay- Berne liquid crystals are calculated. The sixth rank order parameters of these liquid crystals are compared.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
2
v.
3
no.
2012
8
20
http://jrmbs.scu.ac.ir/article_10439_e9bca15f89ad7186a9ef3fbff50bccac.pdf
Electronic and magnetic properties of diluted magnetic semiconductor thin films Zn1-xMnxO
Manouchehr
Babaeipour
عضو هیأت علمی دانشگاه همدان
author
Fariba
Imanian
دانش آموخته کارشناسی ارشد دانشگاه آزاد اسلامی گیلان غرب
author
text
article
2012
per
The structural, electronic and magnetic properties of Zn1-xMnxO dilute magnetic semiconductor (DMS) were studied by the full potential-linear augmented plane wave (FP-LAPW), and for the exchange correlation potential, Generalized Gradient approximation (GGA) was used. The study was done in the framework of the density functional theory (DFT) by implementing the Wien2k code. The density of states showed spin polarization in Fermi level by substitution of Mn atom in the ZnO compound. The values of spin polarization depend on the crystallography structure of Zinc Oxide. Also, the magnetic moment and the exchange splitting energy demonstrated different values for each structure.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
2
v.
3
no.
2012
21
27
http://jrmbs.scu.ac.ir/article_10440_9cb3bc8a42ef2c518904eaa33c2fb098.pdf
Synthesis and characterization of ZnO nanowires using electrodeposition and thermal oxidation and their application as field emitter
Farid
Jamali-Sheini
عضو هیأت علمی دانشگاه آزاد اسلامی اهواز
author
Ramin
Yousefi
عضو هیأت علمی دانشگاه آزاد اسلامی واحد مسجدسلیمان
author
text
article
2012
per
ZnO nanocrystalline thin films were synthesized using cathodic reduction of Zn foil in aqueous electrolyte containing ZnCl2 and H2O2, followed by annealing at 400 oC in the air. The X-ray diffraction pattern exhibited a set of well-defined diffraction peaks corresponding to the ZnO wurtzite phase. Scanning electron microscope and transmission electron microscope images clearly revealed formation of randomly oriented ZnO nanowires having length up to several microns and diameter of ~ 100 nm. The field an emission studies were carried out in a planar diode configuration at a base pressure ~ 1x10-8 mbar. The turn-on field value, required to draw emission current density of 0.1 mA/cm2 was found to be ~ 1.2 V/mm. The Folwer-Nordheim (F-N) plot showed non-linear behavior in the entire range of applied field indicating the semiconducting nature of the emitter. The simplicity of the synthesis route, coupled with the better emission properties, proposes the electrochemically synthesized ZnO nanowire emitter as a promising electron source for high current density applications.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
2
v.
3
no.
2012
28
34
http://jrmbs.scu.ac.ir/article_10441_1eed0d088919db24e166d097d4b030e3.pdf
The Effect of Annealing Temperature on Structural, Electrical and Magnetic Properties of La0.9Sr0.1MnO3 Manganite
Parviz
Kameli
عضو هیأت علمی دانشگاه صنعتی اصفهان
author
Mahin
Eshraghi
عضو هیأت علمی دانشگاه پیام نور
author
Mahboubeh
Roshanmehr
دانش آموخته کارشناسی ارشد دانشگاه پیام نور
author
Fatemeh
Khademi
دانش اموخته کارشناسی ارشد دانشگاه صنعتی اصفهان
author
text
article
2012
per
In this study, a manganite sample with a nominal formula of La0.9Sr0.1MnO3 was prepared by the microwave assisted sol-gel method and annealing at various temperatures. The structural and magnetic properties of the samples were investigated by XRD, FESEM and AC susceptometer, respectively. XRD analysis showed that the samples are a nearly single phase. FESEM micrographs showed that by increasing the annealing temperature from 600 to 1200 oC the size of particles increased from about 50 nm to micrometer. It was also found that the width of paramagnetic-ferromagnetic transition temperature and the magnitude of the susceptibility of samples decrease and increase by increasing annealing temperature, respectively. Also, in the resistivity curves of the micrometer particle sized samples, intergarnular and intragranular phase transition peaks were observed, while the intragranular peak was not seen in the nanometer particle sized sample. These behaviors are related to the surface effects.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
2
v.
3
no.
2012
35
41
http://jrmbs.scu.ac.ir/article_10442_ec06de9989b7b5ce2907fd00e8980e95.pdf
An investigation of coexistence between superconductivity and ferromagnetism in ferromagnetic superconductors
Hamidreza
Emamipour
عضو هیأت علمی دانشگاه ایلام
author
text
article
2012
per
In this paper, we investigate the coexistence between superconductivity and ferromagnetism in a ferromagnetic superconductor (FS) where FS is in antiparallel cooper pairing state and parallel cooper pairing state. By using spin generalized Bogoliubov de Gennes (SBdG) equations, we derive the superconducting order parameter of FS as a function of temperature (T) and exchange field (h) of FS. We find that for some values of T and h the order parameter behaves as a multi-value function, so to determine the physical value of order parameter we calculate the difference in thermodynamic potential between superconducting and normal states, and we present a phase diagram of an FS in T-h plane which separates the superconducting region from the normal region. As a result, we deduce that the non-zero order parameter is not sufficient for having superconducting state and it is necessary to calculate the difference in thermodynamic potential of normal and superconducting states. In other word, in some points of T and h, although there are non-zero order parameters, since in these points the thermodynamic potential of the normal state is lower than the superconducting state, the system falls into the normal state.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
2
v.
3
no.
2012
42
49
http://jrmbs.scu.ac.ir/article_10443_d24d93adea8822ac673cf8ec4cdaa19b.pdf