Nature of the ferromagnetic ground state in the Mn-4 molecular magnet / Streltsov S. V.,Pchelkina Z. V.,Khomskii D. I.,Skorikov N. A.,Anokhin A. O.,Shvachko Yu. N.,Korotin M. A.,Anisimov V. I.,Ustinov V. V. // PHYSICAL REVIEW B. - 2014. - V. 89, l. 1.

ISSN/EISSN:

1098-0121 / 1550-235X

Type:

Article

Abstract:

Using ab initio band-structure and model calculations, we studied magnetic properties of one of the Mn-4 molecular magnets {[}Mn-4(hmp)(6)], where two types of the Mn ions exist: Mn3+ and Mn2+. The direct calculation of the exchange constants in the GGA+U approximation shows that in contrast to a common belief, the strongest exchange coupling is not between two Mn3+ ions (J(bb)), but along two out of four exchange paths connecting Mn3+ and Mn2+ ions (J(wb)). Within the perturbation theory, we performed the microscopic analysis of different contributions to the exchange constants, which allows us to establish the mechanism for the largest ferromagnetic exchange. In the presence of the charge order, the lowest in energy virtual excitations, contributing to the superexchange, will not be those across the Hubbard gap similar to U, but will be those between the Mn3+ and Mn4+ ions, which cost much smaller energy V (<< U). Together with strong Hund's rule coupling and specific orbital order, this leads to large ferromagnetic exchange interaction for two out of four Mn2+-Mn3+ pairs.

Author keywords:

ELECTRONIC-STRUCTURE; MANGANESE COMPLEXES; RELAXATION; SPECTRA; DFT

DOI:

10.1103/PhysRevB.89.014427

Web of Science ID:

ISI:000332332300003

Соавторы в МНС:

Другие поля

Поле	Значение
Month	JAN 30
Publisher	AMER PHYSICAL SOC
Address	ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
Language	English
Article-Number	014427
EISSN	1550-235X
Keywords-Plus	ELECTRONIC-STRUCTURE; MANGANESE COMPLEXES; RELAXATION; SPECTRA; DFT
Research-Areas	Physics
Web-of-Science-Categories	Physics, Condensed Matter
Author-Email	streltsov@imp.uran.ru
ResearcherID-Numbers	Streltsov, Sergey/A-6674-2012 Ustinov, Vladimir/G-7501-2011 Skorikov, Nikolay/A-6728-2012 Pchelkina, Zlata/J-8477-2013 Streltsov, Sergey/A-8293-2016 Anokhin, Anatoly/K-5813-2013 Korotin, Michael/J-3252-2013 Anisimov, Vladimir/K-1235-2013
ORCID-Numbers	Streltsov, Sergey/0000-0002-2823-1754 Ustinov, Vladimir/0000-0002-5155-7947 Skorikov, Nikolay/0000-0002-3771-8708 Pchelkina, Zlata/0000-0002-5588-9009 Anokhin, Anatoly/0000-0001-7431-8933 Korotin, Michael/0000-0002-9603-8374 Anisimov, Vladimir/0000-0002-1087-1956
Funding-Acknowledgement	Russian Foundation for Basic Research {[}RFFI-13-02-00374, RFFI-13-02-00050, RFFI-12-02-31331, RFFI 12-02-91371]; Ministry of Education and Science of Russia {[}12.740.11.0026, MK-3443.2013.2]; Ministry of Education and Science of Russia (FCP program); Samsung corporation via the GRO grant; DFG via 1346 program; Cologne University via the German excellence initiative; Russian Academy of Sciences {[}12M-23-2054, 12-P-2-1017, 12-CD-2]; DFG {[}1484/2-1]
Funding-Text	The authors thank D. Starichenko, who stimulated this study and participated in many interesting discussions about the magnetic properties of the molecular magnets, and A. Katanin and A. Mogilner for providing computational resources and support. This work is supported by the Russian Foundation for Basic Research (Grants No. RFFI-13-02-00374, No. RFFI-13-02-00050, No. RFFI-12-02-31331, No. RFFI 12-02-91371), the Ministry of Education and Science of Russia (Grants No. 12.740.11.0026, No. MK-3443.2013.2, and FCP program), Samsung corporation via the GRO grant, by DFG via 1346 program and Research Grant No. 1484/2-1, by Cologne University via the German excellence initiative, and by Russian Academy of Sciences (Programs No. 12M-23-2054, No. 12-P-2-1017, No. 12-CD-2). The calculations were performed on the ``Uran{''} cluster of the IMM UB RAS.
Number-of-Cited-References	50
Usage-Count-Since-2013	22
Journal-ISO	Phys. Rev. B
Doc-Delivery-Number	AC2LJ