We report the structural, optical, ferroelectric, and dielectric properties of reduced BaTiO3 samples. For this purpose, oxygen vacancies in BaTiO3 are created by heating these samples with a Ti metal in a vacuum environment at different temperatures. It is observed that with an increase in oxygen deficiencies, the c/a ratio decreases as compared to that of the oxygen treated sample. The ferroelectric properties of the oxygen deficient samples are visibly different as compared to those of the oxygen treated sample. The disappearance of the P-E loop and the anomaly in the temperature variation of the dielectric constant have been observed; however, the structural phase transition corresponding to ferroelectric phase transitions still persists. Thus, it appears that the anomaly in dielectric data and the presence of the P-E loop are getting masked possibly by the Maxwell-Wagner effect. The presence of Ti+3 states in the prepared samples has been confirmed by X-ray absorption near edge structure measurements. The Kubelka-Munk optical absorption shows the presence of extra states below fundamental transition, indicating the emergence of new electronic states within the bandgap, which might be due to Ti+3 states. These new states appear at different energy positions, and with different intensities for different samples, which are reduced in the presence of Ti. These new states within the bandgap appear to modify the electronic structure, thereby reducing the overall bandgap, and hence, they seem to modify the ferroelectric and dielectric properties of the samples. Our results may be treated as experimental evidence for theoretically proposed defect states in oxygen deficient or reduced BaTiO3.

1.
F.
Jona
and
G.
Shirane
,
Ferroelectric Crystals
(
Dover Publications, Inc.
,
New York
,
1993
).
2.
M. M.
Vijatovic
,
J. D.
Bobic
, and
B. D.
Stojanovic
,
Sci. Sintering
40
,
155
(
2008
).
3.
W. J.
Merz
,
Phys. Rev.
76
,
1221
(
1949
).
4.
See http://www.doitpoms.ac.uk/tlplib/ferroelectrics/phase_changes.php for section “Barium titanate and phase changes”, for the description of various phase transformations as a function of temperature in BaTiO3.
5.
D. M.
Smyth
,
Annu. Rev. Mater. Sci.
15
,
329
(
1985
).
6.
J.
Buban
,
H.
Iddir
, and
S.
Ohut
,
Phys. Rev. B
69
,
180102(R)
(
2004
).
7.
W.
Luo
,
W.
Duan
,
S. G.
Louie
, and
M. L.
Cohen
,
Phys. Rev. B
70
,
214109
(
2004
).
8.
H.
Donnerberg
and
A.
Birkholz
,
J. Phys.: Condens. Matter
12
,
8239
(
2000
).
9.
C. H.
Park
and
D. J.
Chadi
,
Phys. Rev. B
57
,
R13961
(
1998
).
10.
D.
Ricci
,
G.
Bano
,
G.
Pacchioni
, and
F.
Illas
,
Phys. Rev. B
68
,
224105
(
2003
).
11.
D. D.
Cuong
,
B.
Lee
,
K. M.
Choi
,
H. S.
Ahn
,
S.
Han
, and
J.
Lee
,
Phys. Rev. Lett.
98
,
115503
(
2007
).
12.
K. H.
Hardtl
and
R.
Wernicke
,
Solid State Commun.
10
,
153
(
1972
).
13.
D. C.
Sinclair
,
J. M. S.
Skale
,
F. D.
Morrison
,
R. I.
Smith
, and
T. P.
Beales
,
J. Mater. Chem.
9
,
1327
(
1999
).
14.
V.
Fritsch
 et al,
Phys. Rev. B
64
,
045113
(
2001
).
15.
J.
Huang
 et al,
Phys. Rev. B
82
,
214109
(
2010
).
16.
I. K.
Jeong
 et al,
Phys. Rev. B
84
,
064125
(
2011
).
17.
T.
Kolodiazhnyi
,
M.
Kawaji
,
H.
Hwang
, and
E.
Takayama-Muromachi
,
Phys. Rev. Lett.
104
,
147602
(
2010
).
18.
O.
Saburi
,
J. Phys. Soc. Jpn.
14
,
1159
(
1959
).
19.
Y. C.
Chen
,
J. Mar. Sci. Technol.
15
(
4
),
307
(
2007
); available at http://jmst.ntou.edu.tw/marine/search2.php?keyin=15(4).
20.
B.
Ertug
,
Am. J. Eng. Res.
2
,
01
(
2013
); available at http://www.ajer.org/v2(8).html.
21.
S.
Lee
,
Z.-K.
Liu
,
M.
Kim
, and
C. A.
Randall
,
J. Appl. Phys.
101
,
054119
(
2007
).
22.
T.
Kolodiazhnyi
,
Phys. Rev. B
78
,
045107
(
2008
).
23.
J.
Fujika
,
A.
Doi
 et al,
Sci. Rep.
5
,
13207
(
2015
).
24.
M. B.
Smith
,
K.
Page
,
T.
Siegrist
,
P. L.
Redmond
,
E. C.
Walter
,
R.
Seshadri
,
L. E.
Brus
, and
M. L.
Steigerwald
,
J. Am. Chem. Soc.
130
,
6955
(
2008
).
25.
P.
Bharathi
and
K. B. R.
Varma
,
J. Appl. Phys.
116
,
164107
(
2014
).
26.
Y.
Su
and
G. J.
Weng
,
J. Appl. Phys.
100
,
114110
(
2006
).
27.
G.
Arlt
and
P.
Sasko
,
J. Appl. Phys.
51
(
9
),
4956
(
1980
).
28.
Y.
Bai
,
X.
Han
,
X.-C.
Zheng
, and
L.
Qiao
,
Sci. Rep.
3
,
2895
(
2013
).
29.
S. K.
Upadhyay
,
V. R.
Reddy
, and
N.
Lakshmi
,
J. Asian Ceram. Soc.
1
,
346
350
(
2013
).
30.
T.
Nakatani
,
A.
Yoshiasa
,
A.
Nakatsuka
,
T.
Hiratoko
,
T.
Mashimo
,
M.
Okube
, and
S.
Sasaki
,
Acta. Crystallogr., Sect. B
72
,
151
(
2016
).
31.
B.
Jaffe
,
W. R.
Cook
, and
H.
Jaffe
,
Piezoelectric Ceramics
(
Academic Press
,
New York
,
1971
), Vol.
3
.
32.
M. E.
Lines
and
A. M.
Glass
,
Principles and Applications of Ferroelectrics and Related Materials
(
Clarendon Press
,
Oxford
,
1977
).
33.
B. A.
Strukov
and
A. P.
Levanyuk
,
Ferroelectric Phenomena in Crystals
(
Springer-Verlag
,
Berlin
,
1998
).
34.
J.
Yu
,
P.-F.
Paradis
,
T.
Ishikawa
, and
S.
Yoda
,
Appl. Phys. Lett.
85
,
2899
(
2004
).
35.
M. A.
Subramanian
 et al,
J. Solid State Chem.
151
,
323
(
2000
).
36.
Lunkenheimer
 et al,
Phys. Rev. B
66
,
052105
(
2002
).
37.
A. P.
Remirez
 et al,
Solid State Commun.
115
,
217
(
2000
).
38.
J. C.
Zhao
 et al,
Ceram. Int.
38
,
1221
(
2012
).
39.
W.
Hu
 et al,
Nat. Mater.
12
,
821
(
2013
).
40.
A.
Sagdeo
,
K.
Gautam
,
P. R.
Sagdeo
,
M. N.
Singh
,
S. M.
Gupta
,
A. K.
Nigam
,
R.
Rawat
,
A. K.
Sinha
,
H.
Ghosh
,
T.
Ganguli
, and
A.
Chakrabarti
,
Appl. Phys. Lett.
105
,
042906
(
2014
).
41.
H. M.
Rai
,
S. K.
Saxena
,
R.
Late
,
V.
Mishra
,
P.
Rajput
,
A.
Sagdeo
,
R.
Kumar
, and
P. R.
Sagdeo
,
RSC Adv.
6
,
26621
(
2016
).
42.
H.
Han
,
C.
Voisin
,
S. G.
Frtsch
,
P.
Dufour
,
C.
Tenailleau
,
C.
Turner
, and
J. C.
Nino
,
J. Appl. Phys.
113
,
024102
(
2013
).
43.
J. B.
Goodenough
,
Annu. Rev. Mater. Sci.
28
,
1
(
1998
).
44.
M.-Q.
Cai
,
Y.-J.
Zhang
,
Z.
Yin
, and
M.-S.
Zhang
,
Phys. Rev. B
72
,
075406
(
2005
).
45.
K.-i.
Sakayori
 et al,
Jpn. J. Appl. Phys., Part 1
34
,
5443
(
1995
).
46.
R.
Scharfschwerdt
,
A.
Mazur
,
O. F.
Schirmer
,
H.
Hesse
, and
S.
Mendricks
,
Phys. Rev. B
54
,
15284
(
1996
).
47.
D. D.
Cuong
and
J.
Lee
,
Integr. Ferroelectr.
84
,
23
(
2006
).
48.
T.
Chakraborty
,
C.
Meneghini
,
G.
Aquilanti
, and
S.
Ray
,
J. Phys.: Condens. Matter
25
,
236002
(
2013
).
49.
I.
Qasim
,
P. E. R.
Blanchard
,
B. J.
Kennedy
,
C. D.
Ling
,
L.
Jang
,
T.
Kamiyama
,
P.
Miao
, and
S.
Torii
,
Dalton Trans.
43
,
6909
(
2014
).
50.
J. P.
Itie
,
B.
Couzinet
,
A. C.
Dhaussy
,
A. M.
Flank
,
N.
Jaouen
,
P.
Lagarde
, and
A.
Polian
,
High Pressure Res.
26
,
325
(
2006
).
51.
R.
Courths
,
Phys. Status Solidi B
100
,
135
(
1980
).
52.
V.
Srihari
,
V.
Sridharan
,
S.
Chandra
,
V. S.
Sastry
,
H. K.
Sahu
, and
C. S.
Sundar
,
J. Appl. Phys.
109
,
013510
(
2011
).
53.
G.
Koschek
and
E.
Kubalek
,
Phys. Status Solidi A
79
,
131
(
1983
).
54.
J.
Daniels
and
K. H.
Hardtl
,
Philips Res. Rep.
31
,
489
(
1976
).
55.
D. I.
Woodward
,
I. M.
Reaney
,
G. Y.
Yang
,
E. C.
Dickey
, and
C. A.
Randall
,
Appl. Phys. Lett.
84
,
4650
(
2004
).
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