Hi,
Its easy to compare the Ferrimagnetic (FIM) state with  nonmagnetic (NM) or 
ferromagnetic (FM) state.  If you have two different sublattices then your 
system will converge to a FIM sate during SCF, e.g., Fe3O4, where Fe has two 
different sublattices, i.e, Octahedral and Tetrahedral. FIM is a kind of 
antiferromagnetic (AFM) structure. In AFM we have zero magnetic moment whereas 
FIM has some finite value.  I will considered different types of AFM 
structures, and will do calculations in the NM, FM, and AFM sates and will 
compare their total energies. Keep in mind that you must use the same number of 
atoms in the unit cell to compare their total energies, to minimize numerical 
errors. 
You can also handle it by using Fixed Moment Calculations, where you constrain 
your system with certain magnetic values.  Hope it can help you.
Gul
 


Gul Rahman Ph.D.,
Postdoctoral fellow,
Computational Metallurgy Laboratory (CML),
Graduate Institute of Ferrous Technology (GIFT),
Pohang University of Science and Technology (POSTECH),
Jigok-dong 166-6, Nam-gu,
Pohang 790-834, Republic of Korea (South) 
Fax # 82(0)542799299

--- On Thu, 7/15/10, Juliana Morbec <[email protected]> wrote:


From: Juliana Morbec <[email protected]>
Subject: [SIESTA-L] ferrimagnetic state
To: [email protected]
Date: Thursday, July 15, 2010, 6:44 AM


Dear Siesta users,


I would like to simulate a ferrimagnetic state of a system, in order to compare 
its energetic stability with the ferromagnetic and nonmagnetic state. 
How can do this in a Siesta calculation?


Thanks in advance!

Juliana M. Morbec
------------------------------------------------------------------------------------------------------
Prof. Dr. Juliana M. Morbec      
Theoretical Condensed Matter Physics
Universidade Federal de Alfenas (Federal University of Alfenas - Brazil)
Tel: ++ 55 35 3299 1459
Homepage: http://tinyurl.com/jmorbec
------------------------------------------------------------------------------------------------------



      

Responder a