Crystal structure, phase transitions and magnetic properties of pyrrhotite-type compounds Fe7-xTixS8 / Baranov N. V.,Ibrahim P. N. G.,Selezneva N. V.,Kazantsev V. A.,Volegov A. S.,Shishkin D. A. // PHYSICA B-CONDENSED MATTER. - 2014. - V. 449, l. . - P. 229-235.

ISSN/EISSN:

0921-4526 / 1873-2135

Type:

Article

Abstract:

A series of Fe7-xTixS8 compounds with Ti concentrations up to x=4 has been synthesized by solid state reactions. The substitution of Ti for Fe in pyrrhotite (Fe7S8) modifies its crystal structure from the initial monoclinic 4C superstructure of the NiAs-type to the hexagonal 3C superstructure at x = 1 and then to the 2C monoclinic superstructure at x >= 2. The structural phase transition associated with the disordering of vacancies in metallic layers is found to persist in all the compounds. The growth of the Ti content in Fe7-xTixS8 is accompanied by a gradual decrease of the magnetic ordering temperature from similar to 590 K at x=0 down to 145 K at x=4, by a substantial increase of the low-temperature coercive field (up to 24 kOe) and reduction of the effective magnetic moment from similar to 5.8 mu(B) to 4.3 mu(B). Unlike ferrimagnetic order in Fe7S8, the compound Fe6Ti1S8 shows an antiferromagnetic behavior, while further growth of the Ti concentration above x=2 increases the resultant magnetization up to a value almost in twice higher than the value for non-substituted Fe7S8. Such non-monotonous changes in magnetization behavior with increasing Ti concentration are ascribed to the preferential substitution of Ti for Fe in alternating metallic layers. (C) 2014 Elsevier B.V. All rights reserved.

Author keywords:

Fe7-xTixS8; Pyrrhotite; Superstructure Structural phase transition; Magnetic order; Coercive field NEUTRON-DIFFRACTION; POWDER DIFFRACTION; FE7S8; MOSSBAUER; PRESSURE; FES; SPECTROSCOPY; DOMAINS

DOI:

10.1016/j.physb.2014.05.040

Web of Science ID:

ISI:000339656100040

Соавторы в МНС:

Другие поля

Поле	Значение
Month	SEP 15
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
EISSN	1873-2135
Keywords-Plus	NEUTRON-DIFFRACTION; POWDER DIFFRACTION; FE7S8; MOSSBAUER; PRESSURE; FES; SPECTROSCOPY; DOMAINS
Research-Areas	Physics
Web-of-Science-Categories	Physics, Condensed Matter
Author-Email	baranov@imp.uran.ru
ResearcherID-Numbers	kazantsev, vadim/J-5186-2013 Baranov, Nikolai/J-5042-2013 Shishkin, Denis/K-5766-2013
ORCID-Numbers	kazantsev, vadim/0000-0003-2407-6280 Baranov, Nikolai/0000-0002-9720-5314 Shishkin, Denis/0000-0001-5225-3120
Funding-Acknowledgement	Russian Foundation for Basic Research {[}13-02-00364, 13-02-96038]; program of the Ural Branch of RAS {[}12-T-2-1012]; government of Sverdlovsk region
Funding-Text	This work was supported by the Russian Foundation for Basic Research (Projects nos. 13-02-00364 and 13-02-96038), by the program of the Ural Branch of RAS (Project no. 12-T-2-1012) and by the government of Sverdlovsk region. The authors are grateful to Dr. A.A. Titov for his assistance in experiment.
Number-of-Cited-References	33
Usage-Count-Last-180-days	3
Usage-Count-Since-2013	44
Journal-ISO	Physica B
Doc-Delivery-Number	AM2CL