Here, we report the temperature-dependent electrical resistivity and thermopower of hole (Sr) and electron (Hf) doped LaCoO3 in the range of 303–753 K. With increasing temperature, the insulating behavior (303–503 K) with dominance of small polaron hopping to metallic transition (>503 K) is observed. The electron doped sample shows an insulating behavior ( 19.5 Ω cm ) and positive thermopower (139 μV K−1) value due to the spin state blockade, i.e., electron hopping from high spin Co2+ to low spin Co3+ is strongly inhibited. The calculated weighted mobility ( μ W ) of 0.01 to 0.96 cm 2 V 1 s 1 validates the observed spin blockade mechanism in electron doped LaCoO3. The fluctuation of spin/orbital ordering and point defect scattering results in the low thermal conductivity of 0.5 W m 1 K 1 for Hf doped LaCoO3. The spin state blockade observed in the electrical resistivity and low lattice thermal conductivity reveals that spin state transition drives the thermoelectric response in Mott insulator LaCoO3.

1.
I.
Terasaki
,
Y.
Sasago
, and
K.
Uchinokura
, “
Large thermoelectric power in single crystals
,”
Phys. Rev. B
56
(
20
),
R12685
R12687
(
1997
).
2.
J.
Wooldridge
,
D.
Mck Paul
,
G.
Balakrishnan
, and
M. R.
Lees
, “
Investigation of the spin density wave in NaxCoO2
,”
J. Phys.: Condens. Matter
17
(
4
),
707
718
(
2005
).
3.
Y.
Moritomo
,
K.
Higashi
,
K.
Matsuda
, and
A.
Nakamura
, “
Spin-state transition in layered perovskite cobalt oxide (0.4⩽x⩽1.0)
,”
Phys. Rev. B
55
(
22
),
R14725
R14728
(
1997
).
4.
S.
Ru
,
J.
Chen
,
Y.
Chin
,
M.
Valldor
,
Z.
Hu
,
J.
Lee
,
S.
Haw
,
N.
Hiraoka
,
H.
Ishii
,
C.
Pao
et al, “
A complete high-to-low spin state transition of trivalent cobalt ion in octahedral symmetry in SrCo0.5Ru0.5O3-δ
,”
J. Am. Chem. Soc.
136
,
1514
1519
(
2014
).
5.
C.
Frontera
,
J. L.
García-Muñoz
,
A.
Llobet
,
L.
Mañosa
, and
M. A. G.
Aranda
, “
Selective spin-state and metal-insulator transitions in GdBaCo2O5.5
,”
J. Solid State Chem.
171
(
1–2
),
349
352
(
2003
).
6.
S.
Yamaguchi
,
Y.
Okimoto
,
H.
Taniguchi
, and
Y.
Tokura
, “
Spin-state transition and high-spin polarons in LaC
,”
Phys. Rev. B
53
(
6
),
R2926
R2929
(
1996
).
7.
M.
Abbate
,
J. C.
Fuggle
,
A.
Fujimori
,
L. H.
Tjeng
,
C. T.
Chen
,
R.
Potze
,
G. A.
Sawatzky
,
H.
Eisaki
, and
S.
Uchida
, “
Electronic structure and spin-state transition of LaCoO3
,”
Phys. Rev. B
47
(
24
),
16124
(
1993
).
8.
M. A.
Señarís-Rodríguez
and
J. B.
Goodenough
, “
LaCoO3 revisited
,”
J. Solid State Chem.
116
,
224
231
(
1995
).
9.
I.
Terasaki
,
S.
Shibasaki
,
S.
Yoshida
, and
W.
Kobayashi
, “
Spin state control of the perovskite Rh/Co oxides
,”
Materials
3
(
2
),
786
799
(
2010
).
10.
Z.
Jirák
,
J.
Hejtmánek
,
K.
Knížek
, and
M.
Veverka
, “
Electrical resistivity and thermopower measurements of the hole- and electron-doped cobaltites LnCoO3
,”
Phys. Rev. B
78
(
1
),
014432
(
2008
).
11.
A.
Maignan
,
D.
Flahaut
, and
S.
Hébert
, “
Sign change of the thermoelectric power in LaCoO3
,”
Eur. Phys. J. B
39
(
2
),
145
148
(
2004
).
12.
K. P.
Mohamed Jibri
,
J.
Archana
,
M.
Navaneethan
, and
S.
Harish
, “
Small polaron hopping conduction mechanism and enhanced thermoelectric power factor in the perovskite LaCoO3 ceramic
,”
Phys. Chem. Chem. Phys.
25
(
18
),
12914
12922
(
2023
).
13.
K. P.
Mohamed Jibri
,
A.
Rengarjan
,
N.
Mani
, and
H.
Santhana Krishnan
, “
Elucidation of superior thermoelectric transport properties via tuning hopping potential barrier, mass, and strain field fluctuations in LaCo0.95A0.05O3 (A = Y, In)
,”
J. Phys. Chem. C
127
(
24
),
11707
11711
(
2023
).
14.
A.
Maignan
,
V.
Caignaert
,
B.
Raveau
,
D.
Khomskii
, and
G.
Sawatzky
, “
Thermoelectric power of HoBaCo2O5.5: Possible evidence of the spin blockade in cobaltites
,”
Phys. Rev. Lett.
93
(
2
),
026401
(
2004
).
15.
A. A.
Taskin
and
Y.
Ando
, “
Electron-hole asymmetry in GdBaCo2O5+x: Evidence for spin blockade of electron transport in a correlated electron system
,”
Phys. Rev. Lett.
95
(
17
),
176603
(
2005
).
16.
Z.
Liu
,
Y.
Sakai
,
J.
Yang
,
W.
Li
,
Y.
Liu
,
X.
Ye
,
S.
Qin
,
J.
Chen
,
S.
Agrestini
,
K.
Chen
et al, “
sequential spin state transition and intermetallic charge transfer in PbCoO3
,”
J. Am. Chem. Soc.
142
(
12
),
5731
5741
(
2020
).
17.
J.
Hwang
,
Z.
Feng
,
N.
Charles
,
X. R.
Wang
,
D.
Lee
,
K. A.
Stoerzinger
,
S.
Muy
,
R. R.
Rao
,
D.
Lee
,
R.
Jacobs
et al, “
Tuning perovskite oxides by strain: electronic structure, properties, and functions in (electro)catalysis and ferroelectricity
,”
Mater. Today
31
,
100
118
(
2019
).
18.
Y.
Sun
,
X.
Ren
,
S.
Sun
,
Z.
Liu
,
S.
Xi
, and
Z. J.
Xu
, “
Engineering high-spin state cobalt cations in spinel zinc cobalt oxide for spin channel propagation and active site enhancement in water oxidation
,”
Angew. Chem. Int. Ed.
60
(
26
),
14536
14544
(
2021
).
19.
M.
Christensen
,
S.
Johnsen
, and
B. B.
Iversen
, “
Thermoelectric clathrates of type I
,”
Dalton Trans.
39
(
4
),
978
992
(
2010
).
20.
A.
Kumar
,
K.
Kumari
,
S. J.
Ray
, and
A. D.
Thakur
, “
Graphene mediated resistive switching and thermoelectric behavior in lanthanum cobaltate
,”
J. Appl. Phys.
127
(
23
),
235103
(
2020
).
21.
A.
Doi
,
S.
Shimano
,
M.
Kriener
,
A.
Kikkawa
,
Y.
Taguchi
, and
Y.
Tokura
, “
Positive temperature coefficient of the thermal conductivity above room temperature in a perovskite cobaltite
,”
Sci. Technol. Adv. Mater.
23
(
1
),
858
865
(
2022
).
22.
K.
Wang
,
Q.
Yang
,
H.
Zhang
,
M.
Zhang
,
H.
Jiang
,
C.
Zheng
, and
J.
Li
, “
Recent advances in catalyst design and activity enhancement induced by a magnetic field for electrocatalysis
,”
J. Mater. Chem. A
11
(
15
),
7802
7832
(
2023
).
23.
K.
Iwasaki
,
T.
Ito
,
T.
Nagasaki
,
Y.
Arita
,
M.
Yoshino
, and
T.
Matsui
, “
Thermoelectric properties of polycrystalline La1−XSrXCoO3
,”
J. Solid State Chem.
181
(
11
),
3145
3150
(
2008
).
24.
Y.
Wang
,
Y.
Sui
,
P.
Ren
,
L.
Wang
,
X.
Wang
,
W.
Su
, and
H. J.
Fan
, “
Correlation between the structural distortions and thermoelectric characteristics in La1−XAXCoO3 (A = Ca and Sr)
,”
Inorg. Chem.
49
(
7
),
3216
3223
(
2010
).
25.
M. A.
Bousnina
,
F.
Giovannelli
,
L.
Perriere
,
G.
Guegan
, and
F.
Delorme
, “
Ba substitution for enhancement of the thermoelectric properties of LaCoO3 ceramics (0 ⩽ x ⩽ 0.75)
,”
J. Adv. Ceram.
8
(
4
),
519
526
(
2019
).
26.
S.
Hébert
,
D.
Flahaut
,
C.
Martin
,
S.
Lemonnier
,
J.
Noudem
,
C.
Goupil
,
A.
Maignan
, and
J.
Hejtmanek
, “
Thermoelectric properties of perovskites: Sign change of the Seebeck coefficient and high temperature properties
,”
Prog. Solid State Chem.
35
(
2–4
),
457
467
(
2007
).
27.
R.
Robert
,
D.
Logvinovich
,
M. H.
Aguirre
,
S. G.
Ebbinghaus
,
L.
Bocher
,
P.
Tomeš
, and
A.
Weidenkaff
, “
Crystal structure, morphology and physical properties of LaCo1−XTiXO3±δ perovskites prepared by a citric acid assisted soft chemistry synthesis
,”
Acta Mater.
58
(
2
),
680
691
(
2010
).
28.
Y.
Tokura
,
Y.
Okimoto
,
S.
Yamaguchi
,
H.
Taniguchi
,
T.
Kimura
, and
H.
Takagi
, “
Thermally induced insulator-metal transition in LaCoO3: A view based on the Mott transition
,”
Phys. Rev. B
58
(
4
),
R1699
R1702
(
1998
).
29.
T.
Kyômen
,
Y.
Asaka
, and
M.
Itoh
, “
Negative cooperative effect on the spin-state excitation in LaCoO3
,”
Phys. Rev. B
67
(
14
),
144424
(
2003
).
30.
K.
Tomiyasu
,
M.
Sato
,
S. I.
Koyama
,
T.
Nojima
,
R.
Kajimoto
,
S.
Ji
, and
K.
Iwasa
, “
Magnetic properties of electron-doped LaCoO3
,”
J. Phys. Soc. Jpn.
86
(
9
),
094706
094708
(
2017
).
31.
P. M.
Raccah
and
J. B.
Goodenough
, “
First-order localized-electron collective-electron transition in LaCoO3
,”
Phys. Rev.
155
(
3
),
932
943
(
1967
).
32.
V. G.
Bhide
,
D. S.
Rajoria
,
G. R.
Rao
, and
C. N. R.
Rao
, “
Mössbauer studies of the high-spin-low-spin equilibria and the localized-collective electron transition in LaCoO3
,”
Phys. Rev. B
6
(
3
),
1021
1032
(
1972
).
33.
M.
Korotin
,
S. Y.
Ezhov
,
I.
Solovyev
,
V.
Anisimov
,
D.
Khomskii
, and
G.
Sawatzky
, “
Intermediate-spin state and properties
,”
Phys. Rev. B
54
(
8
),
5309
5316
(
1996
).
34.
M. W.
Haverkort
,
Z.
Hu
,
J. C.
Cezar
,
T.
Burnus
,
H.
Hartmann
,
M.
Reuther
,
C.
Zobel
,
T.
Lorenz
,
A.
Tanaka
,
N. B.
Brookes
et al, “
Spin state transition in LaCoO3 studied using soft x-ray absorption spectroscopy and magnetic circular dichroism
,”
Phys. Rev. Lett.
97
(
17
),
176405
(
2006
).
35.
K.
Tomiyasu
,
S. I.
Koyama
,
M.
Watahiki
,
M.
Sato
,
K.
Nishihara
,
Y.
Takahashi
,
M.
Onodera
,
K.
Iwasa
,
T.
Nojima
,
H.
Nojiri
et al, “
Microscopic examinations of Co valences and spin states in electron-doped LaCoO3
,”
J. Phys. Soc. Jpn.
85
(
9
),
094702
(
2016
).
36.
W.
Khan
,
A. H.
Naqvi
,
M.
Gupta
,
S.
Husain
, and
R.
Kumar
, “
Small polaron hopping conduction mechanism in Fe doped LaMnO3
,”
J. Chem. Phys.
135
(
5
),
054501
(
2011
).
37.
S. R.
Sehlin
,
H. U.
Anderson
, and
D. M.
Sparlin
, “
Semiempirical model for the electrical properties of La1−XCaxCoO3
,”
Phys. Rev. B
52
(
16
),
11681
11689
(
1995
).
38.
K.
Tanwar
,
D. S.
Gyan
,
S.
Bhattacharya
,
S.
Vitta
,
A.
Dwivedi
, and
T.
Maiti
, “
Enhancement of thermoelectric power factor by inducing octahedral ordering in La2−xSrxCoFe O6 double perovskites
,”
Phys. Rev. B
99
(
17
),
174105
(
2019
).
39.
W.
Kobayashi
,
I.
Terasaki
,
M.
Mikami
, and
R.
Funahashi
, “
Negative thermoelectric power induced by positive carriers in CaMn3−XCuXMn4O12
,”
J. Phys. Soc. Jpn.
73
(
3
),
523
525
(
2004
).
40.
T.
Palstra
,
A.
Ramirez
,
S. W.
Cheong
, and
B.
Zegarski
, “
Transport mechanisms in doped evidence for polaron formation
,”
Phys. Rev. B
56
(
9
),
5104
5107
(
1997
).
41.
W.
Koshibae
,
K.
Tsutsui
, and
S.
Maekawa
, “
Thermopower in cobalt oxides
,”
Phys. Rev. B
62
(
11
),
6869
6872
(
2000
).
42.
A. J. E.
Rettie
,
W. D.
Chemelewski
,
D.
Emin
, and
C. B.
Mullins
, “
Unravelling small-polaron transport in metal oxide photoelectrodes
,”
J. Phys. Chem. Lett.
7
(
3
),
471
479
(
2016
).
43.
G. J.
Snyder
,
A. H.
Snyder
,
M.
Wood
,
R.
Gurunathan
,
B. H.
Snyder
, and
C.
Niu
, “
Weighted mobility
,”
Adv. Mater.
32
(
25
),
2001537
(
2020
).
44.
T.
Katase
,
X.
He
,
T.
Tadano
,
J. M.
Tomczak
,
T.
Onozato
,
K.
Ide
,
B.
Feng
,
T.
Tohei
,
H.
Hiramatsu
,
H.
Ohta
et al, “
Breaking of thermopower–conductivity trade-off in LaTiO3 film around Mott insulator to metal transition
,”
Adv. Sci.
8
(
23
),
2102097
(
2021
).
45.
R.
Gurunathan
,
R.
Hanus
, and
G. J.
Snyder
, “
Alloy scattering of phonons
,”
Mater. Horiz.
7
(
6
),
1452
1456
(
2020
).
46.
J.
Callaway
and
H. C.
von Bayer
, “
Effect of point imperfections on lattice thermal conductivity
,”
Phys. Rev.
120
(
4
),
1149
1154
(
1960
).
47.
Y.
Wang
,
F.
Li
,
L.
Xu
,
Y.
Sui
,
X.
Wang
,
W.
Su
, and
X.
Liu
, “
Large thermal conductivity reduction induced by La/O vacancies in the thermoelectric LaCoO3 system
,”
Inorg. Chem.
50
(
10
),
4412
4416
(
2011
).
48.
J.
Yang
,
G. P.
Meisner
, and
L.
Chen
, “
Strain field fluctuation effects on lattice thermal conductivity of ZrNiSn-based thermoelectric compounds
,”
Appl. Phys. Lett.
85
(
7
),
1140
1142
(
2004
).
49.
X.
He
,
S.
Nomoto
,
T.
Komatsu
,
T.
Katase
,
T.
Tadano
,
S.
Kitani
,
H.
Yoshida
,
T.
Yamamoto
,
H.
Mizoguchi
,
K.
Ide
et al, “
Hydride anion substitution boosts thermoelectric performance of polycrystalline SrTiO3 via simultaneous realization of reduced thermal conductivity and high electronic conductivity
,”
Adv. Funct. Mater.
33
(
28
),
2213144
(
2023
).
50.
C.
Chang
and
L. D.
Zhao
, “
Anharmoncity and low thermal conductivity in thermoelectrics
,”
Mater. Today Phys.
4
,
50
57
(
2018
).
51.
J.
Matsuno
,
J.
Fujioka
,
T.
Okuda
,
K.
Ueno
,
T.
Mizokawa
, and
T.
Katsufuji
, “
Strongly correlated oxides for energy harvesting
,”
Sci. Technol. Adv. Mater.
19
(
1
),
899
908
(
2018
).
You do not currently have access to this content.