We have investigated the transport properties of single crystals of a thermoelectric semimetal Ta2PdSe6 and its niobium-substituted (Ta1−xNbx)2PdSe6 by means of resistivity, thermopower, and Hall resistivity measurements. The residual resistivity ratio systematically decreases by the Nb-substitution, indicating enhanced impurity scattering. The slope and peak-top value of thermopower also systematically decrease upon increasing x. We have analyzed the set of transport data by using a two-carrier model, then revealed strong correlation between the thermopower and carrier mobility in the titled compound. We propose that controlling carrier mobility is a possible route to achieve a high-performance thermoelectric semimetal.

1.
M. N.
Ali
,
J.
Xiong
,
S.
Flynn
,
J.
Tao
,
Q. D.
Gibson
,
L. M.
Schoop
,
T.
Liang
,
N.
Haldolaarachchige
,
M.
Hirschberger
,
N. P.
Ong
, and
R. J.
Cava
,
Nature
514
,
205
(
2014
).
2.
T.
Kaneko
,
Y.
Ohta
, and
S.
Yunoki
,
Phys. Rev. B
97
,
155131
(
2018
).
3.
H.
Cercelier
,
C.
Monney
,
F.
Clerc
,
C.
Bataglia
,
L.
Despont
,
M. G.
Garnier
,
H.
Beck
,
P.
Aebi
,
L.
Patthey
,
H.
Benger
, and
L.
Forro
,
Phys. Rev. Lett
99
,
146403
(
2007
).
4.
C.
Shekhar
,
A. K.
Nayak
,
Y.
Sun
,
M.
Schmidt
,
M.
Nicklas
,
I.
Leemakers
,
U.
Zeitler
,
Y.
Skourski
,
J.
Wonsnitza
,
Z.
Liu
,
Y.
Chen
,
W.
Schnelle
,
H.
Borrmann
,
Y.
Grin
,
C.
Flese
, and
B.
Yan
,
Nat. Phys.
11
,
645
(
2015
).
5.
T.
Liang
,
Q.
Gibson
,
M. N.
Ali
,
M.
Liu
,
R. J.
Cava
, and
N. P.
Ong
,
Nat. Mater.
14
,
280
(
2015
).
6.
M.
Markov
,
X.
Hu
,
H.
Liu
,
N.
Liu
,
S. J.
Poon
,
K.
Esfarjani
, and
M.
Zebarjadi
,
Sci. Rep.
8
,
9876
(
2018
).
7.
M.
Markov
,
S. E.
Rezaei
,
S. N.
Sadeghi
,
K.
Esfarjani
, and
M.
Zebarjadi
,
Phys. Rev. Mater.
3
,
095401
(
2019
).
8.
G. J.
Snyder
and
E. S.
Toberer
,
Nat. Mater.
7
,
105
(
2008
).
9.
J.
Wang
,
R.
Zhao
,
M.
Yang
,
Z.
Liu
, and
A.
Liu
,
J. Chem. Phys.
138
,
084701
(
2013
).
10.
G. D.
Mahan
,
Solid State Phys.
51
,
81
(
1998
).
11.
A.
Nakano
,
T.
Nagai
,
N.
Katayama
,
H.
Sawa
,
H.
Taniguchi
, and
I.
Terasaki
,
J. Phys. Soc. Jpn.
88
,
113706
(
2019
).
12.
Y.
Pan
,
F.
Fan
,
X.
Hong
,
B.
He
,
C.
Le
,
W.
Schnelle
,
Y.
He
,
K.
Imasato
,
H.
Borrmann
,
C.
Hess
,
B.
Buchner
,
Y.
Sun
,
C.
Fu
,
G. J.
Snyder
, and
C.
Felser
,
Adv. Mater.
33
,
2003168
(
2021
).
13.
J.
Mao
,
G.
Chen
, and
Z.
Ren
,
Nat. Mater.
20
,
454
(
2021
).
14.
A.
Nakano
,
A.
Yamakage
,
U.
Maruoka
,
H.
Taniguchi
,
Y.
Yasui
, and
I.
Terasaki
,
J. Phys. Energy
3
,
044004
(
2021
).
15.
D. A.
Keszler
,
P. J.
Squattrito
,
N. E.
Brese
,
J. A.
Ibers
,
M.
Shang
, and
J.
Lu
,
Inorg. Chem.
24
,
3063
(
1985
).
16.
K.
Monma
and
F.
Izumi
,
J. Appl. Cryst.
41
,
653
(
2008
).
17.
18.
H.
Takahashi
,
Y.
Yasui
,
I.
Terasaki
, and
M.
Sato
,
J. Phys. Soc. Jpn.
80
,
054708
(
2011
).
19.
C.
Zhang
,
Z.
Yuan
,
Q.
Jiang
,
B.
Tong
,
C.
Zhang
,
X. C.
Xie
, and
S.
Jia
,
Phys. Rev. B
95
,
085202
(
2017
).
20.
A.
Nakano
,
U.
Maruoka
,
F.
Kato
,
H.
Taniguchi
, and
I.
Terasaki
,
J. Phys. Soc. Jpn.
90
,
033702
(
2021
).
21.
T. J.
Scheidemantel
,
C.
Ambrosch-Draxl
,
T.
Thonhause
,
J. V.
Badding
, and
J. O.
Sofo
,
Phys. Rev. B
68
,
125210
(
2003
).

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