کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5420067 | 1507403 | 2009 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nature of the magnetic interaction between Fe-porphyrin molecules and ferromagnetic surfaces
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Nature of the magnetic interaction between Fe-porphyrin molecules and ferromagnetic surfaces Nature of the magnetic interaction between Fe-porphyrin molecules and ferromagnetic surfaces](/preview/png/5420067.png)
چکیده انگلیسی
We have investigated computationally the magnetic spin state of free metalloporphyrins and how magnetic ordering in metalloporphyrins can be induced through contact with the metallic surface and what the origin of the exchange interaction is. To this end, we performed density functional theory (DFT) and DFTÂ +Â U studies for a series of isolated, ligated as well as unligated Fe-porphyrin (FeP) molecules as well as various FeP molecules on surfaces. Our calculations for isolated FePs clearly demonstrate that the usual DFT-based exchange-correlation functionals (such as the generalized gradient approximation) cannot predict the experimental high-spin ground state of these molecules. Instead, one has to resort to DFTÂ +Â U calculations with a Coulomb U of about 4Â eV on the Fe atoms, to obtain the correct single-molecule spin state. The magnetic interaction between FeP and a Co surface has been studied computationally with the DFT and DFTÂ +Â U approaches. Our total energy DFT and DFTÂ +Â U calculations predict an optimal Fe - substrate distance of 3.5Â Ã
and a ferromagnetic exchange coupling of FeP to the substrate, in accordance with recent experiments. For Fe-porphyrin chloride (FePCl), on the other hand, an antiferromagnetic coupling is computed to be more favorable. Our study demonstrates that due to an indirect exchange interaction, which is mediated through the four nitrogen atoms, ferromagnetic ordering on the FeP is stabilized.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Surface Science - Volume 84, Issues 1â2, March 2009, Pages 18-29
Journal: Progress in Surface Science - Volume 84, Issues 1â2, March 2009, Pages 18-29
نویسندگان
P.M. Oppeneer, P.M. Panchmatia, B. Sanyal, O. Eriksson, Md.E. Ali,