Fluorides K0.5FeF3 with tetragonal tungsten bronze structure have been fabricated by solid state reaction at low sintering temperature in the range between 150 °C and 400 °C with the assistance of crystal water during the grinding and sintering processes. Unusual magnetic properties have been observed, including positive exchange bias field (HE) with negative vertical magnetization shift (Mshift), and smaller field cooling (FC) magnetization than the zero field cooling one below 53 K. The results are explained by a core-shell structure consisting of antiferromagnetic core and spin glass (SG) shell with antiferromagnetic interfacial coupling between the pinned interface spins and the SG shell spins. The sign of HE and Mshift can be changed by increasing the cooling field in the FC process, which is attributed to the competition between the antiferromagnetic interfacial coupling and the Zeeman energy of magnetization of the SG shell.

1.
W.
Eerenstein
,
N. D.
Mathur
, and
J. F.
Scott
,
Nature
442
,
759
(
2006
).
2.
K. F.
Wang
,
J.-M.
Liu
, and
Z. F.
Ren
,
Adv. Phys.
58
,
321
(
2009
).
3.
N. A.
Hill
,
J. Phys. Chem. B
104
,
6694
(
2000
).
4.
J. F.
Scott
and
R.
Blinc
,
J. Phys.: Condens. Matter
23
,
113202
(
2011
).
5.
F.
Mezzadri
,
S.
Fabbrici
,
E.
Montanari
,
L.
Righi
,
G.
Calestani
,
E.
Gilioli
,
F.
Bolzoni
, and
A.
Migliori
,
Phys. Rev. B
78
,
064111
(
2008
), and references therein.
6.
E.
Banks
,
M.
Shone
,
R. F.
Williamson
, and
W. O. J.
Boo
,
Inorg. Chem.
22
,
3339
(
1983
).
7.
R.
Blinc
,
G.
Tavčar
,
B.
Žemva
,
D.
Hanžel
,
P.
Cevc
,
C.
Filipič
,
A.
Levstik
,
Z.
Jagličič
,
Z.
Trontelj
,
N.
Dalal
,
V.
Ramachandran
,
S.
Nellutla
, and
J. F.
Scott
,
J. Appl. Phys.
103
,
074114
(
2008
).
8.
Sk.
Mohammad Yusuf
,
L.
Madhav Rao
,
R.
Mukhopadhyay
,
S.
Giri
,
K.
Ghoshray
, and
A.
Ghoshray
,
Solid State Commun.
101
,
145
(
1997
).
9.
S.
Giri
and
K.
Ghoshray
,
Phys. Rev. B
57
,
5918
(
1998
).
10.
See supplementary material at http://dx.doi.org/10.1063/1.4820476 for the analysis of the XRD pattern of K0.5FeF3 prepared at 150 °C, the preparation with and without crystal water, and the dc magnetic relaxation measurement.
11.
L.
Chen
,
Y.
Yang
, and
X.
Meng
,
Appl. Phys. Lett.
102
,
203102
(
2013
).
12.
P. K.
Manna
,
S. M.
Yusuf
,
R.
Shukla
, and
A. K.
Tyagi
,
Appl. Phys. Lett.
96
,
242508
(
2010
).
13.
S.
Giri
,
K.
Ghoshray
, and
A.
Ghoshray
,
Solid State Commun.
93
,
493
(
1995
).
14.
B.
Song
,
J.
Jian
,
H.
Bao
,
M.
Lei
,
H.
Li
,
G.
Wang
,
Y.
Xu
, and
X.
Chen
,
Appl. Phys. Lett.
92
,
192511
(
2008
).
15.
S.
Dhar
,
O.
Brandt
,
A.
Trampert
,
K. J.
Friedland
,
Y. J.
Sun
, and
K. H.
Ploog
,
Phys. Rev. B
67
,
165205
(
2003
).
16.
B.
Antic
,
G. F.
Goya
,
H. R.
Rechenberg
,
V.
Kusigerski
,
N.
Jovic
, and
M.
Mitric
,
J. Phys.: Condens. Matter
16
,
651
(
2004
).
17.
J. Y.
Yu
,
S. L.
Tang
,
X. K.
Zhang
,
L.
Zhai
,
Y. G.
Shi
,
Y.
Deng
, and
Y. W.
Du
,
Appl. Phys. Lett.
94
,
182506
(
2009
).
18.
C.
Díaz-Guerra
,
M.
Vila
, and
J.
Piqueras
,
Appl. Phys. Lett.
96
,
193105
(
2010
).
19.
R. P.
Singh
and
C. V.
Tomy
,
J. Phys.: Condens. Matter.
20
,
235209
(
2008
).
20.
A. A.
Belik
,
Inorg. Chem.
52
,
2015
(
2013
).
21.
S.
Karmakar
,
S.
Taran
,
E.
Bose
,
B. K.
Chardhuri
,
C. P.
Sun
,
C. L.
Huang
, and
H. D.
Yang
,
Phys. Rev. B
77
,
144409
(
2008
).
22.
H.
Duan
,
S.
Yuan
,
X.
Zheng
, and
Z.
Tian
,
Chin. Phys. B
21
,
078101
(
2012
).
23.
S. K.
Giri
,
A.
Poddar
, and
T. K.
Nath
,
J. Appl. Phys.
112
,
113903
(
2012
).
24.
W.
Zhang
,
T.
Wen
, and
K. M.
Krishnan
,
Appl. Phys. Lett.
101
,
132401
(
2012
).
25.
J.
Nogués
,
C.
Leighton
, and
I. K.
Schuller
,
Phys. Rev. B
61
,
1315
(
2000
).
26.
M.
Ali
,
P.
Adie
,
C. H.
Marrow
,
D.
Greig
,
B. J.
Hickey
, and
R. L.
Stamps
,
Nature Mater.
6
,
70
(
2007
).
27.
F.
Yuan
,
J.
Lin
,
Y. D.
Yao
, and
S.
Lee
,
Appl. Phys. Lett.
96
,
162502
(
2010
).
28.
X. H.
Huang
,
J. F.
Ding
,
G. Q.
Zhang
,
Y.
Hou
,
Y. P.
Yao
, and
X. G.
Li
,
Phys. Rev. B
78
,
224408
(
2008
).

Supplementary Material

You do not currently have access to this content.