[Pw_forum] hysteresis Loop

[Seyed Javad Hashemifar]

I am not sure but my understanding is that studying hysteresis phenomena
needs to phenomenological models and I doubt if it is possible to study
directly this macroscopic phenomena by first principles calculations without
any phenomenology. As far as I know husteresis is s macroscopic phenomena
wich originates from domain structure of the system. For example in the case
of ferromagnetic hysteresis, the magnetic domain structure of the system
give rises to hysteresis effect. Hence I guess you have to develop or find a
phenomenological model based on some physical parameters such as domain wall
energy to be able to draw hysteresis loop. The physical parameters of
phenomenological models could be calculated by direct first principles
computations.

SJ Hashemifar

======================================
Seyed Javad  Hashemifar
Physics Department, Isfahan University of Technology
84156-83111 Isfahan, Iran
Tel: +98 311 391 2375     Fax:+98 311 3912376
Email:  hashemifar at cc.iut.ac.ir
Homepage:  http://hashemifar.iut.ac.ir
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On Thu, Jul 7, 2011 at 6:17 PM, Mahdi Mirnezhad <mirnezhad.mm at gmail.com>wrote:

> Dear Developers,
> I want to study the hysteresis loop by using the DFT calculation.
>
> We want to draw a graph of residual stress (strain).
>
> DFT
> simply calculates the Ground State of the physical system, it is not
> involve the memory of system. Could any body introduce me a DFT or
> "DFT like" method for this kind of calculations?
> Thanks in advance
>
>
> Mahdi Mirnezhad
> MSc student of Mechanical engineering,
> Guilan University.
>
>
> On 7/7/11, Gabriele Sclauzero <sclauzer at sissa.it> wrote:
> > Il giorno 06/lug/2011, alle ore 23.39, Mahdi Mirnezhad ha scritto:
> >
> >> Dear Developers,
> >> I want to study the hysteresis loop by using the DFT calculation.
> >
> > Hysteresis loops can arise in several physics phenomena and in different
> > situations, so it is not clear to me what you are referring to.
> > Please make your question more specific, for instance by pointing to some
> > work in the scientific literature! Are you speaking about dynamics,
> > magnetism, other...?
> >
> >
> > GS
> >
> >> DFT
> >> simply calculates the Ground State of the physical system, it is not
> >> involve the memory of system. Could any body introduce me a DFT or
> >> "DFT like" method for this kind of calculations?
> >> Thanks in advance
> >>
> >>
> ----------------------------------------------------------------------------
> >> Mahdi Mirnezhad
> >> MSc student of Mechanical engineering,
> >> Guilan University.
> >> _______________________________________________
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://www.democritos.it/mailman/listinfo/pw_forum
> >
> >
> > § Gabriele Sclauzero, EPFL SB ITP CSEA
> >    PH H2 462, Station 3, CH-1015 Lausanne
> >
> >
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