The spontaneous exchange bias (SEB) effect is a remarkable phenomenon recently observed in some reentrant spin-glass materials. Here, we investigate the SEB in La1.5(Sr0.5−xBax)CoMnO6 double-perovskites, a system with multifarious magnetic phases for which a notable increase in the exchange bias field is observed for intermediate Sr/Ba concentrations. The Ba to Sr substitution leads to the enhancement of the crystal lattice, which is accompanied by the increase in both the effective magnetic moment (μeff) and the antiferromagnetic (AFM) transition temperature that is observed below the ferromagnetic ordering. Such an increase is likely related to the increased fraction of Co3+ in the high spin configuration, leading to the enhancement of the Co3+–O–Mn4+ AFM phase and the reduction in the uncompensation of the AFM coupling between Co and Mn. The combined effect of the increased μeff and AFM phase plausibly explains the changes in the SEB effect.

1.
J.
Nogués
and
I. K.
Schuller
,
J. Magn. Magn. Mater.
192
,
203
(
1999
).
2.
B. M.
Wang
,
Y.
Liu
,
P.
Ren
,
B.
Xia
,
K. B.
Ruan2
,
J. B.
Yi
,
J.
Ding
,
X. G.
Li
, and
L.
Wang
,
Phys. Rev. Lett.
106
,
0077203
(
2011
).
3.
T.
Maity
,
S.
Goswami
,
D.
Bhattacharya
, and
S.
Roy
,
Phys. Rev. Lett.
110
,
107201
(
2013
).
4.
A. K.
Nayak
,
M.
Nicklas
,
S.
Chadov
,
C.
Shekhar
,
Y.
Skourski
,
J.
Winterlik
, and
C.
Felser
,
Phys. Rev. Lett.
110
,
127204
(
2013
).
5.
L. T.
Coutrim
,
E. M.
Bittar
,
F.
Garcia
, and
L.
Bufaiçal
,
Phys. Rev. B
98
,
064426
(
2018
).
6.
L.
Bufaiçal
,
L. T.
Coutrim
,
E. M.
Bittar
, and
F.
Garcia
,
J. Magn. Magn. Mater.
512
,
167048
(
2020
).
7.
S.
Vasala
and
M.
Karppinen
,
Prog. Solid State Chem.
43
,
1
(
2015
).
8.
J. A.
Mydosh
,
Spin Glasses: An Experimental Introduction
(
Taylor & Francis
,
London
,
1993
).
9.
J.
Krishna Murthy
and
A.
Venimadhav
,
Appl. Phys. Lett.
103
,
252410
(
2013
).
10.
M.
Boldrin
,
L. T.
Coutrim
, and
L.
Bufaiçal
,
Braz. J. Phys.
50
,
711
(
2020
).
11.
L.
Bufaiçal
,
R.
Finkler
,
L. T.
Coutrim
,
P. G.
Pagliuso
,
C.
Grossi
,
F.
Stavale
,
E.
Baggio-Saitovitch
, and
E. M.
Bittar
,
J. Magn. Magn. Mater.
433
,
271
(
2017
).
12.
L. T.
Coutrim
,
D.
Rigitano
,
C.
Macchiutti
,
T. J. A.
Mori
,
R.
Lora-Serrano
,
E.
Granado
,
E.
Sadrollahi
,
F. J.
Litterst
,
M. B.
Fontes
,
E.
Baggio-Saitovitch
,
E. M.
Bittar
, and
L.
Bufaiçal
,
Phys. Rev. B
100
,
054428
(
2019
).
13.
B.
Raveau
and
M. M.
Seikh
,
Cobalt Oxides: From Crystal Chemistry to Physics
(
Wiley-VCH
,
Weinheim
,
2012
).
14.
A. C.
Larson
and
R. B.
Von Dreele
,
Report No. LAUR 86-748
(Los Alamos National Laboratory,
2000
);
B. H.
Toby
,
J. Appl. Crystallogr.
34
,
210
(
2001
).
15.
R. D.
Shannon
,
Acta Crystallogr., Sect. A
32
,
751
(
1976
).
16.
C. J.
Howard
,
B. J.
Kennedy
, and
P. M.
Woodward
,
Acta Crystallogr., Sect. B
59
,
463
(
2003
).
17.
L.
Xie
and
H. G.
Zhang
,
Curr. Appl. Phys.
18
,
261
(
2018
).
18.
J. K.
Murthy
,
K. D.
Chandrasekhar
,
H. C.
Wu
,
H. D.
Yang
,
J. Y.
Lin
, and
A.
Venimadhav
,
J. Phys.: Condens. Matter
28
,
086003
(
2016
).

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