Re: [Wien] elast for magnetic material + curie temp
What does it mean "we are able to predict them as spintronic" ? There is nothing to predict a material as spintronic, maybe they are some ferromagnets, ferrimagnets, antiferromagnets, or otherspecial cases of magnetism that you can predict. If you like to predict something for ambient conditions that is room temperature and normal pressure than you may use some extensions of Wien as for example Phonon and Gibbs 2 codes and to check wether the Curie temperature is below or above room temperature. Again if you like to know the elastic constants you should know whether or not your compound is in the ferromagnetic or the paramagnetic state or even in some other magnetic state that might be a non collinear ferrimagnet or helical magnet. Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden Von: wien-boun...@zeus.theochem.tuwien.ac.at [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von Murugan Sundareswari [sundare65w...@gmail.com] Gesendet: Donnerstag, 20. August 2015 06:28 An: A Mailing list for WIEN2k users; pbl...@theochem.tuwien.ac.at; Gavin Abo Betreff: [Wien] elast for magnetic material + curie temp We are working on predicted full Heusler compounds and for some of them...we are able to predict them as spintronic. so far we have not calculated the curie temp..and also since it is predicted compound we are not able to find the experimental data so far. Is it possible to calculate curie temperature with our code. we are calculating the elastic constants at ambient condition for the above mentioned ferromagnetic materialsand still i have the doubt of using the structure file of magnetic or non-magnetic to do so? Looking Forward to your response, Best Regards, sundare [https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif] ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] elast for magnetic material + curie temp
The Curie temperature can be roughly estimated from a comparison of the total energies of the ferromagnetic and the antiferromagnetic states. For a better way please check our book Felser/Fecher Spintronics: From materials to devices published by Springer and in particular the chapter by Kübler Fecher Felser. You will need to calculate the exchange coupling constants Jij either in real or in momentum space (Note that one form is found from the Fourier transformation of the other and vice versa). The latter you can do with the non collinear spin code of Wien2k see also: Kübler Fecher Felser, Understanding the trend in the Curie temperatures of Co2-based Heusler compounds: Ab initio calculations; in Phys. Rev. B 76, 024414 (2007) (Indeed, this method works also for Neel temperatures) Before you try such things, be sure that you know very well what you are doing Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden Von: wien-boun...@zeus.theochem.tuwien.ac.at [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von Xavier Rocquefelte [xavier.rocquefe...@univ-rennes1.fr] Gesendet: Donnerstag, 20. August 2015 10:08 An: A Mailing list for WIEN2k users Betreff: Re: [Wien] elast for magnetic material + curie temp About the Néel temperature, I know two main strategies: - If you know an analytical formula which relates TN with J values (J: magnetic exchange parameters of your system) then you can estimate TN from DFT calculations. It will require the calculation of all the J's values of your system. Such a calculation of TN is possible for simple systems for which the analytical equation is known (one-dimensional Heisenberg magnetic system). - In a more general case, you need to include the temperature fluctuation effects on your magnetic system. To do this, you must go beyond DFT. For instance, doing Monte-Carlo calculations using DFT paramaters will allow you to estimate TN. Cheers Xavier Lyudmila Dobysheva a écrit : > 20.08.2015 07:28, Murugan Sundareswari ?: >> Is it possible to calculate curie temperature with our code. > I am not in the know of Curie temperature > >> we are calculating the elastic constants at ambient condition for the >> above mentioned ferromagnetic materialsand still i have the doubt of >> using the structure file of magnetic or non-magnetic to do so? > > Making a calculational model that correctly simulate concrete samples > and their experimental data is the most important thing, it cannot be > done without knowing all tiny details of the task, and it takes, > imho, 80 % of time to work out it. After this, one can quickly > calculate properties, this is a routine work. > So, nobody can answer you. We can only give you some small hints, for > example: >> On Tue, Aug 18, 2015 at 1:32 PM, Fecher, Gerhard > Depends, do you like to calculate for above or below the Curie temperature ? > > Best wishes > Lyudmila Dobysheva > -- > Phys.-Techn. Institute of Ural Br. of Russian Ac. of Sci. > 426001 Izhevsk, ul.Kirova 132I am not in the know of Curie temperature > RUSSIA > -- > Tel.:7(3412) 432045(office), 722529(Fax) > E-mail: l...@ftiudm.ru, lyuk...@mail.ru (office) > lyuk...@gmail.com (home) > Skype: lyuka17 (home), lyuka18 (office) > http://ftiudm.ru/content/view/25/103/lang,english/ > -- > ___ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html > ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] elast for magnetic material + curie temp
About the Néel temperature, I know two main strategies: - If you know an analytical formula which relates TN with J values (J: magnetic exchange parameters of your system) then you can estimate TN from DFT calculations. It will require the calculation of all the J's values of your system. Such a calculation of TN is possible for simple systems for which the analytical equation is known (one-dimensional Heisenberg magnetic system). - In a more general case, you need to include the temperature fluctuation effects on your magnetic system. To do this, you must go beyond DFT. For instance, doing Monte-Carlo calculations using DFT paramaters will allow you to estimate TN. Cheers Xavier Lyudmila Dobysheva a écrit : > 20.08.2015 07:28, Murugan Sundareswari ?: >> Is it possible to calculate curie temperature with our code. > I am not in the know of Curie temperature > >> we are calculating the elastic constants at ambient condition for the >> above mentioned ferromagnetic materialsand still i have the doubt of >> using the structure file of magnetic or non-magnetic to do so? > > Making a calculational model that correctly simulate concrete samples > and their experimental data is the most important thing, it cannot be > done without knowing all tiny details of the task, and it takes, > imho, 80 % of time to work out it. After this, one can quickly > calculate properties, this is a routine work. > So, nobody can answer you. We can only give you some small hints, for > example: >> On Tue, Aug 18, 2015 at 1:32 PM, Fecher, Gerhard > Depends, do you like to calculate for above or below the Curie temperature ? > > Best wishes > Lyudmila Dobysheva > -- > Phys.-Techn. Institute of Ural Br. of Russian Ac. of Sci. > 426001 Izhevsk, ul.Kirova 132I am not in the know of Curie temperature > RUSSIA > -- > Tel.:7(3412) 432045(office), 722529(Fax) > E-mail: l...@ftiudm.ru, lyuk...@mail.ru (office) > lyuk...@gmail.com (home) > Skype: lyuka17 (home), lyuka18 (office) > http://ftiudm.ru/content/view/25/103/lang,english/ > -- > ___ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html >___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] elast for magnetic material + curie temp
20.08.2015 07:28, Murugan Sundareswari пишет: Is it possible to calculate curie temperature with our code. I am not in the know of Curie temperature we are calculating the elastic constants at ambient condition for the above mentioned ferromagnetic materialsand still i have the doubt of using the structure file of magnetic or non-magnetic to do so? Making a calculational model that correctly simulate concrete samples and their experimental data is the most important thing, it cannot be done without knowing all tiny details of the task, and it takes, imho, 80 % of time to work out it. After this, one can quickly calculate properties, this is a routine work. So, nobody can answer you. We can only give you some small hints, for example: > On Tue, Aug 18, 2015 at 1:32 PM, Fecher, Gerhard wrote: > Depends, do you like to calculate for above or below the Curie temperature ? Best wishes Lyudmila Dobysheva -- Phys.-Techn. Institute of Ural Br. of Russian Ac. of Sci. 426001 Izhevsk, ul.Kirova 132I am not in the know of Curie temperature RUSSIA -- Tel.:7(3412) 432045(office), 722529(Fax) E-mail: l...@ftiudm.ru, lyuk...@mail.ru (office) lyuk...@gmail.com (home) Skype: lyuka17 (home), lyuka18 (office) http://ftiudm.ru/content/view/25/103/lang,english/ -- ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
[Wien] elast for magnetic material + curie temp
We are working on predicted full Heusler compounds and for some of them...we are able to predict them as spintronic. so far we have not calculated the curie temp..and also since it is predicted compound we are not able to find the experimental data so far. Is it possible to calculate curie temperature with our code. we are calculating the elastic constants at ambient condition for the above mentioned ferromagnetic materialsand still i have the doubt of using the structure file of magnetic or non-magnetic to do so? Looking Forward to your response, Best Regards, sundare ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
