The effect of the microstructure on the antiferromagnetic to ferromagnetic transition in FeRh alloys / Chirkova A.,Bittner F.,Nenkov K.,Baranov N. V.,Schultz L.,Nielsch K.,Woodcock T. G. // ACTA MATERIALIA. - 2017. - V. 131, l. . - P. 31-38.

ISSN/EISSN:

1359-6454 / 1873-2453

Type:

Article

Abstract:

A detailed study of Fe48Rh52 samples heat treated at different temperatures (1123 K, 1273 K and 1423 K) has been performed using scanning and transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction and magnetic measurements. The microstructure of all samples consisted of alpha' (B2) and gamma (A1) phases. Although the chemical composition, chemical ordering and the lattice parameter of the magnetic alpha' phase in all three samples did not vary with heat treatment temperature, the temperature of the metamagnetic transition between the antiferromagnetic (AFM) and ferromagnetic (FM) states varied by 50 K. No gradients in chemical composition on a length scale larger than approximately 10 nm exist at the alpha'/gamma phase boundaries. Due to the 1\% volume expansion of the alpha' phase, which occurs during the AFM-FM transition, stress fields around the alpha'/gamma phase boundaries are expected. The composition, lattice, parameter, size, shape and distribution of the gamma phase was shown to change with heat treatment temperature. Finite element models indicated that these microstructural parameters influence the magnitude and extent of the stress fields at the phase boundaries. The variation in the transition temperature is therefore ascribed to the differences in the stress fields. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Author keywords:

Heat treatment; Annealing; Electron microscopy; Magnetocaloric effect; Mechanical stress fields MAGNETIC TRANSITIONS; PHASE-TRANSITIONS; ROOM-TEMPERATURE; RECORDING MEDIA; IRON-RHODIUM; THIN-FILMS; RH ALLOYS; GIANT; DEPENDENCE

DOI:

10.1016/j.actamat.2017.04.005

Web of Science ID:

ISI:000402343400004

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	JUN 1
Publisher	PERGAMON-ELSEVIER SCIENCE LTD
Address	THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Language	English
EISSN	1873-2453
Keywords-Plus	MAGNETIC TRANSITIONS; PHASE-TRANSITIONS; ROOM-TEMPERATURE; RECORDING MEDIA; IRON-RHODIUM; THIN-FILMS; RH ALLOYS; GIANT; DEPENDENCE
Research-Areas	Materials Science; Metallurgy \& Metallurgical Engineering
Web-of-Science-Categories	Materials Science, Multidisciplinary; Metallurgy \& Metallurgical Engineering
Author-Email	a.chirkova@ifw-dresden.de
ResearcherID-Numbers	Baranov, Nikolai/J-5042-2013
ORCID-Numbers	Baranov, Nikolai/0000-0002-9720-5314
Funding-Acknowledgement	Graduate Academy of the TU Dresden; Program of the Ural Branch of RAS {[}15-17-2-22]
Funding-Text	We are very grateful to K. Berger and A. Pohl for the samples preparation and assistance with microscopy, C. Mickel and Dr. B. Rellinghaus for provision of TEM facilities, Dr. S. Wurmehl and her colleagues for use of some equipment and discussions, and we appreciate fruitful discussions with T. Mix, Dr. A. Volegov (Ural Federal University), Dr. M. Gorshenkov (MiSIS), Dr. S. Fahler, Dr. A. Waske, Dr. M. Krautz, Dr. K-H Muller, Dr. O. Shuleshova. All are from IFW Dresden unless stated otherwise. The financial support by the Graduate Academy of the TU Dresden is acknowledged. N.V. Baranov acknowledges the support by the Program of the Ural Branch of RAS (Project No 15-17-2-22).
Number-of-Cited-References	35
Usage-Count-Last-180-days	49
Usage-Count-Since-2013	49
Journal-ISO	Acta Mater.
Doc-Delivery-Number	EW2RJ