Calculation of thermodynamic properties of two-dimensional liquid helium-3
Gholam Hossein
Bordbar
Professor of Physics/Shiraz University
author
فاطمه
شاکر
دانشجو/دانشگاه شیراز
author
text
article
2014
per
We have used a many-body method based on the cluster expansion of the energy to calculate the free energy, entropy, equation of state, heat capacity and incompressibility of the two dimensional liquid helium-3. In these calculations, we have used the Lennard-Jones potential as the inter atomic interaction. Our calculations show that the free energy increases by increasing the density, and decreases by increasing temperature. We have also shown that the two dimensional liquid helium-3 has no bond state. Our results indicate that the equation of state of the system becomes stiffer as the temperature increases. For heat capacity, it was seen that reaches the limiting value 1 k_B at high temperatures. This means that our system has a behavior the same as two dimensional classical ideal gas. Also, our results have shown that as the density and temperature increase, the system becomes more incompressible.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
3
v.
6
no.
2014
1
7
http://jrmbs.scu.ac.ir/article_10896_c80d4e91923758378feba44dfbc7b15d.pdf
dx.doi.org/10.22055/jrmbs.2014.10896
Electronic and optical properties of Cu2-II-IV-VI4(II=Zn,Cd; IV=Ge,Sn; VI=S,Se,Te) quaternary chalcogenides using GGA and mBJ-GGA approximations
mehrdad
dadsetani
عضو هیئت علمی دانشگاه لرستان
author
Razieh
Momeni feili
مربی حق التدریس
author
Azadeh
Beiranvand
مربی حق التدریس
author
text
article
2014
per
Electronic and optical properties of Cu2-II-IV-VI4(II=Zn,Cd; IV=Ge,Sn; VI=S,Se,Te) quaternary chalcogenides are calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT) and the calculated results are compared with the available experimental results. The real and imaginary parts of the dielecteric function ԑ(ω), the electron energy loss function (EELS) and the optical absorption coefficient I(ω) are calculated within the random phase approximation (RPA). The prominent structures in the specrta of ԑ1(ω), ԑ2(ω) and EELS are discussed in detail and the static dielectric constants of these compounds are calculated . The most prominent feature of these compounds is their high absorption coefficient and wide absorption spectrum. It is an appropriate parameter for using in solar cells. The band structures are calculated using Perdew et al., Engel-Vosko and modified Becke-Johnson schemes and the effect of the exchange-correlation functional on the band gap of these compounds is investigated. It is shown that mBJ-GGA leads to a better result.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
3
v.
6
no.
2014
9
24
http://jrmbs.scu.ac.ir/article_10895_3ecf9019075c11eb14f64434278a0b33.pdf
ُStudy of magnetic and electronic properties of NdMnO3 manganite using LSDA and LSDA+U approximations
حسن
آریانی محمدیه
دانشگاه شاهرود
author
ء
قاضی
دانشگاه شاهرود
author
مرتضی
ایزدی فرد
دانشگاه شاهرود
author
text
article
2014
per
In this paper, we study the NdMnO3 manganite compound based on the density function theory and using the local spin density LSDA and local spin density plus Hubbard energy LSDA+U approximations. The magnetic and electronic structures of this system were studied using these approximations. After the optimization of volume and structure parameters, the ground state magnetic phase, magnetic moments of atoms and local and total density of states of the atoms were calculated by considering different Hubbard energy. The results of ground state energy showed that although the ferromagnetic and anti-ferromagnetic phases are in competition but the ferromagnetic phase is more stable. The magnetic moments and the density of states calculated from LSDA+U lead to reasonable result but LSDA results are not accurate. The results of density of states indicated that the 3d orbitals of Mn atom, contributed in conduction and hybridization, are the most effective orbital in magnetic properties of the compound.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
3
v.
6
no.
2014
25
37
http://jrmbs.scu.ac.ir/article_10894_b85bbcea03d314f5997c5feaa77b09cd.pdf
Investigation of Er deformed isotopes by Partial Dynamical SU(3) Symmetry
ناصر
فولادی
دانشگاه تبریز
author
محمدعلی
جعفریزاده
دانشگاه تبریز
author
جواد
فولادی
دانشگاه تبریز
author
هادی
صبری
دانشگاه تبریز
author
text
article
2014
per
In this paper, we have considered the energy spectra and quadruple transition probabilities of even-even Er isotopes via partial dynamical symmetry in interacting boson model framework. The advantage of using interactions with a partial dynamical symmetry is that they can be introduced, in a controlled manner, without destroying results previously obtained with a dynamical symmetry for a segment of the spectrum. Partial dynamical SU(3) symmetry has an accurate description for nuclei which exhibit rotational deformed structure because of removing undesired degeneracies from energy spectrum of them.The agreement with the most recent experimental counterparts is acceptable. Also, there are some suggestions about the reduction of uncertainty with increasing the neutron number and quadrupole deformation parameter.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
3
v.
6
no.
2014
39
51
http://jrmbs.scu.ac.ir/article_10897_0f2d1b7b793097e6e9044e28fe9ea84e.pdf
Dimer phase in the spin-1/2 frustrated chain
Tayebeh
Nedaee
University of Guilan
author
Saeed
Mahdavifar
Faculty member
University of Guilan
author
text
article
2014
per
In this paper, the frustrated dimerized antiferromagnetic isotropic s=1/2 Heisenberg chain is studied. In this model, denotes the dimerization parameter for the exchange of nearest neighbors and denotes the frustration parameter for the exchange of next nearest neighbor interaction. Using the numerical Lanczos method, we have studied the magnetic phase diagram of the model in two subspaces . We have calculated the response functions of the system as a function of the frustrated parameter. According to the exact diagonalization results, by calculating order parameter, it is argued that, adding the dimerization will cause a phase transition between two different types of dimer phases.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
3
v.
6
no.
2014
53
62
http://jrmbs.scu.ac.ir/article_10898_e187e093f8370d5539bb8f685a773a9f.pdf
Electronic, phononic and mechanical properties of GaN
atefe
nejati
دانشگاه آزاد اسلامی واحد قم
author
faramarz
kanjouri
Kharazmi university
author
hasan
tashakori
islamic azad university of Qom
author
text
article
2014
per
In this paper, the electronic, phononic and mechanical properties of zinc-blende and wurtzite phases of GaN compound are studied by Density Functional Theory (DFT), generalized gradient approximation (GGA) and pseudo potentials. Results show both phases are semiconductors. The calculated band gaps are 2 and 2.2 eV for zinc-blende and wurtzite phases correspondingly. Bulk modules are obtained by fitting the variation of energy vs. the lattice constants data to the murnaghan equation of state. The phonon dispersion curves are obtained in high symmetry directions. The elastic constants are calculated by the slope of the phonon acoustic modes in different directions. These constants are =272, =122 and =127 GPa in zinc-blende phase and =301, =380, =85, =88, =125, =153 GPa in wurtzite phase. Our results are compared with other calculation and are in good agreement with them. Young modules are calculated in tensile and comparison modes for wurtzite phase and compared with zinc-blende phase .The results show; the wurtzite phase is harder in z direction.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
3
v.
6
no.
2014
63
73
http://jrmbs.scu.ac.ir/article_10900_5530846cd2549d575b4827f662fc06fc.pdf