We report the thermoelectric properties of valence fluctuating material α-YbAlB4 along a-, b-, and c-axes. The temperature dependence of the Seebeck coefficient for all axes shows negative peaks at around 250 K, which is close to the Kondo scale. Interestingly, the absolute value of the Seebeck coefficient along c-axis (−75 μV K−1 at 250 K) is larger than those along a- and b-axes (−50 μV K−1 at 250 K) although the electrical resistivity along c-axis is about four times lower than those along a- and b-axes. As a result, a very large thermoelectric power factor of ∼14.5 mW m−1 K−2 is realized along c-axis at 200 K, which is ten times larger than those along a- and b-axes. The anisotropies in electrical resistivity and Seebeck coefficient, respectively, have different origins of Fermi surface and the c-f hybridization, realizing the simultaneous enhancements of thermopower and electrical conductivity.
References
1.
G. D.
Mahan
, Solid State Physics
(Academic Press
, New York
, 1997
), Vol. 56
, pp. 81
–157
.2.
K. F.
Hsu
, S.
Loo
, F.
Guo
, W.
Chen
, J. S.
Dyck
, C.
Uher
, T.
, Hogan
, E. K.
Polychroniadis
, and M. G.
Kanatzidis
, “Cubic AgPbmSbTe
2+m: Bulk thermoelectric materials with high figure of merit
,” Science
303
, 818
(2004
).3.
J. P.
Heremans
, V.
Jovovic
, E. S.
Toberer
, A.
Saramat
, K.
Kurosaki
, A.
Charoenphakdee
, S.
Yamanaka
, and G. J.
Snyder
, “Enhancement of thermoelectric efficiency in PbTe by distortion of the electronic density of states
,” Science
321
, 554
(2008
).4.
B.
Paula
, P. K.
Rawat
, and P.
Banerji
, “Dramatic enhancement of thermoelectric power factor in PbTe:Cr co-doped with iodine
,” Appl. Phys. Lett.
98
, 262101
(2011
).5.
Y.
Pei
, X.
Shi
, A.
LaLonde
, H.
Wang
, L.
Chen
, and G. J.
Snyder
, “Convergence of electronic bands for high performance bulk thermoelectrics
,” Nature
473
, 66
(2011
).6.
M. S.
Dresselhaus
, G.
Chen
, M. Y.
Tang
, R. G.
Yang
, H.
Lee
, D. Z.
Wang
, Z. F.
Ren
, J.-P.
Fleurial
, and P.
Gogna
, “New directions for low-dimensional thermoelectric materials
,” Adv. Mater.
19
, 1043
(2007
).7.
S. V.
Faleev
and F.
Léonard
, “Theory of enhancement of thermoelectric properties of materials with nanoinclusions
,” Phys. Rev. B
77
, 214304
(2008
).8.
D.
Narducci
, E.
Selezneva
, G.
Cerofolini
, S.
Frabboni
, and G.
Ottaviani
, “Impact of energy filtering and carrier localization on the thermoelectric properties of granular semiconductors
,” J. Solid State Chem.
193
, 19
(2012
).9.
R. J.
Gambino
, W. O.
Grobman
, and A. M.
Toxen
, “Anomalously large thermoelectric cooling figure of merit in the Kondo systems CePd3 and Celn3
,” Appl. Phys. Lett.
22
, 506
(1973
).10.
H. J.
van Daal
, P. B.
van Aken
, and K. H. J.
Buschow
, “The seebeck coefficient of YbAl2 and YbAl3
,” Phys. Lett. A
49
, 246
(1974
).11.
V.
Zlatić
and R.
Monnier
, “Theory of the thermoelectricity of intermetallic compounds with Ce or Yb ions
,” Phys. Rev. B
71
, 165109
(2005
).12.
V.
Zlatić
and U.
Stockert
, “Dependence of transport coefficients of Yb(Rh1–xCox)2Si2 intermetallics on temperature and cobalt concentration
,” Phys. Rev. B
101
, 155146
(2020
).13.
N. E.
Bickers
, D. L.
Cox
, and J. W.
Wilkins
, “Self-consistent large-N expansion for normal-state properties of dilute magnetic alloys
,” Phys. Rev. B
36
, 2036
(1987
).14.
G. D.
Mahan
, “Seebeck coefficient for the Anderson model
,” Phys. Rev. B
56
, 11833
(1997
).15.
Z.
Fisk
, K. N.
Yang
, M. B.
Maple
, and H. R.
Ott
, Valence Fluctuations in Solids
(North-Holland Publishing Co
., 1981
).16.
R. T.
Macaluso
, S.
Nakatsuji
, K.
Kuga
, E. L.
Thomas
, Y.
Machida
, Y.
Maeno
, Z.
Fisk
, and J. Y.
Chan
, “Crystal structure and physical properties of polymorphs of LnAlB4 (Ln = Yb, Lu)
,” Chem. Mater.
19
, 1918
(2007
).17.
M.
Okawa
, M.
Matsunami
, K.
Ishizaka
, R.
Eguchi
, M.
Taguchi
, A.
Chainani
, Y.
Takata
, M.
Yabashi
, K.
Tamasaku
, Y.
Nishino
, T.
Ishikawa
, K.
Kuga
, N.
Horie
, S.
Nakatsuji
, and S.
Shin
, “Strong valence fluctuation in the quantum critical heavy fermion superconductor β-YbAlB4: A hard x-ray photoemission study
,” Phys. Rev. Lett.
104
, 247201
(2010
).18.
Y.
Matsumoto
, K.
Kuga
, T.
Tomita
, Y.
Karaki
, and S.
Nakatsuji
, “Anisotropic heavy-Fermi-liquid formation in valence-fluctuating α-YbAlB4
,” Phys. Rev. B
84
, 125126
(2011
).19.
K.
Momma
and F.
Izumi
, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data
,” J. Appl. Crystallogr.
44
, 1272
(2011
).20.
K.
Kuga
, Y.
Kanai
, H.
Fujiwara
, K.
Yamagami
, S.
Hamamoto
, Y.
Aoyama
, A.
Sekiyama
, A.
Higashiya
, T.
Kadono
, S.
Imada
, A.
Yamasaki
, A.
Tanaka
, K.
Tamasaku
, M.
Yabashi
, T.
Ishikawa
, S.
Nakatsuji
, and T.
Kiss
, “Effect of anisotropic hybridization in YbAlB4 probed by linear dichroism in core-level hard x-ray photoemission spectroscopy
,” Phys. Rev. Lett.
123
, 036404
(2019
).21.
V. A.
Greanya
, W. C.
Tonjes
, R.
Liu
, C. G.
Olson
, D.-Y.
Chung
, and M. G.
Kanatzidis
, “Angle-resolved photoemission study of the high-performance low-temperature thermoelectric material CsBi4Te6
,” Phys. Rev. B
65
, 205123
(2002
).22.
P.
Larson
, S. D.
Mahanti
, D.-Y.
Chung
, and M. G.
Kanatzidis
, “Electronic structure of CsBi4Te6: A high-performance thermoelectric at low temperatures
,” Phys. Rev. B
65
, 045205
(2002
).23.
T.
Inohara
, Y.
Okamoto
, Y.
Yamakawa
, A.
Yamakage
, and K.
Takenaka
, “Large thermoelectric power factor at low temperatures in one-dimensional telluride Ta4SiTe4
,” Appl. Phys. Lett.
110
, 183901
(2017
).24.
Y.
Okamoto
, T.
Wada
, Y.
Yamakawa
, T.
Inohara
, and K.
Takenaka
, “Large thermoelectric power factor in one-dimensional telluride Nb4SiTe4 and substituted compounds
,” Appl. Phys. Lett.
112
, 173905
(2018
).25.
Y.
Okamoto
, Y.
Yoshikawa
, T.
Wada
, and K.
Takenaka
, “Hole-doped M4SiTe4 (M = Ta, Nb) as an efficient p-type thermoelectric material for low-temperature applications
,” Appl. Phys. Lett.
115
, 043901
(2019
).26.
U.
Stockert
, C.
Klingner
, C.
Krellner
, V.
Zlatić
, and C.
Geibel
, “Thermopower Evolution in Yb(Rh1–xCox)2Si2 upon 4f localization
,” J. Low Temp. Phys.
196
, 364
(2019
).27.
K.
Alami-Yadri
, H.
Wilhelm
, and D.
Jaccard
, “Transport properties of Yb-compounds at high pressure
,” Physica B
259–261
, 157
(1999
).28.
T. H.
Geballe
and G. W.
Hull
, “Seebeck effect in germanium
,” Phys. Rev.
94
, 1134
(1954
).29.
C.
Herring
, “Theory of the thermoelectric power of semiconductors
,” Phys. Rev.
96
, 1163
(1954
).30.
L.
Weber
and E.
Gmelin
, “Transport properties of silicon
,” Appl. Phys. A
53
, 136
(1991
).31.
K.
Behnia
, D.
Jaccard
, and J.
Flouquet
, “On the thermoelectricity of correlated electrons in the zero-temperature limit
,” J. Phys.
16
, 5187
(2004
).32.
G.
Nakamoto
, T.
Takabatake
, H.
Fujii
, A.
Minami
, K.
Maezawa
, I.
Oguro
, and A. A.
Menovsky
, “Crystal growth and characterization of the Kondo semimetal CeNiSn
,” J. Phys. Soc. Jpn.
64
, 4834
(1995
).33.
S.
Paschen
, B.
Wand
, G.
Sparn
, F.
Steglich
, Y.
Echizen
, and T.
Takabatake
, “Thermal-transport properties of CeNiSn
,” Phys. Rev. B
62
, 14912
(2000
).34.
A. K.
Bhattacharjee
, B.
Coqblin
, M.
Raki
, L.
Forro
, C.
Ayache
, and D.
Schmitt
, “Anisotropy of transport properties in the Kondo compound CePt2Si2: Experiments and theory
,” J. Phys.
50
, 2781
(1989
).35.
L.-D.
Zhao
, S.-H.
Lo
, Y.
Zhang
, H.
Sun
, G.
Tan
, C.
Uher
, C.
Wolverton
, V. P.
Dravid
, and M. G.
Kanatzidis
, “Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals
,” Nature
508
, 373
(2014
).36.
Y.
Pan
, F.-R.
Fan
, X.
Hong
, B.
He
, C.
Le
, W.
Schnelle
, Y.
He
, K.
Imasato
, H.
Borrmann
, C.
Hess
, B.
Büchner
, Y.
Sun
, C.
Fu
, G. J.
Snyder
, and C.
Felser
, “Thermoelectric properties of novel semimetals: A case study of YbMnSb2
,” Adv. Mater.
33
, 2003168
(2021
).37.
A.
Li
, C.
Hu
, B.
He
, M.
Yao
, C.
Fu
, Y.
Wang
, X.
Zhao
, C.
Felser
, and T.
Zhu
, “Demonstration of valley anisotropy utilized to enhance the thermoelectric power factor
,” Nat. Commun.
12
, 5408
(2021
).38.
K.
Lee
, S.
Kamali
, T.
Ericsson
, M.
Bellard
, and K.
Kovnir
, “GeAs: Highly anisotropic van der Waals thermoelectric material
,” Chem. Mater.
28
, 2776
(2016
).39.
M. S.
da Luz
, C. A. M.
dos Santos
, J.
Moreno
, B. D.
White
, and J. J.
Neumeier
, “Anisotropic electrical resistivity of quasi-one-dimensional Li0.9Mo6O17 determined by the Mongometrey method
,” Phys. Rev. B
76
, 233105
(2007
).40.
J. L.
Cohn
, S.
Moshfeghyeganeh
, C. A. M.
dos Santos
, and J. J.
Neumeier
, “Extreme thermopower anisotropy and interchain transport in the quasi-one-dimensional metal Li0.9Mo6O17
,” Phys. Rev. Lett.
112
, 186602
(2014
).41.
P.
Yordanov
, W.
Sigle
, P.
Kaya
, M. E.
Gruner
, R.
Pentcheva
, B.
Keimer
, and H.-U.
Habermeier
, “Large thermopower anisotropy in PdCoO2 thin films
,” Phys. Rev. Mater.
3
, 085403
(2019
).42.
X.
Yan
, B.
Poudel
, Y.
Ma
, W. S.
Liu
, G.
Joshi
, H.
Wang
, Y.
Lan
, D.
Wang
, G.
Chen
, and Z. F.
Ren
, “Experimental studies on anisotropic thermoelectric properties and structures of n-type Bi2Te2.7Se0.3
,” Nano Lett.
10
, 3373
(2010
).43.
H. Q.
Yang
, X. Y.
Wang
, H.
Wu
, B.
Zhang
, D. D.
Xie
, Y. J.
Chen
, X.
Lu
, X. D.
Han
, L.
Miao
, and X. Y.
Zhou
, “Sn vacancy engineering for enhancing the thermoelectric performance of two-dimensional SnS
,” J. Mater. Chem. C
7
, 3351
(2019
).44.
N.
Wang
, M.
Li
, H.
Xiao
, X.
Zu
, and L.
Qiao
, “Layered LaCuOSe: A promising anisotropic thermoelectric material
,” Phys. Rev. Appl.
13
, 024038
(2020
).45.
V.
Askarpour
and J.
Maassen
, “Unusual thermoelectric transport anisotropy in quasi-two-dimensional rhombohedral GeTe
,” Phys. Rev. B
100
, 075201
(2019
).46.
K.
Kuga
, G.
Morrison
, L.
Treadwell
, J. Y.
Chan
, and S.
Nakatsuji
, “Magnetic order induced by Fe substitution of Al site in the heavy-fermion systems α-YbAlB4 and β-YbAlB4
,” Phys. Rev. B
86
, 224413
(2012
).47.
K.
Kuga
, Y.
Matsumoto
, M.
Okawa
, S.
Suzuki
, T.
Tomita
, K.
Sone
, Y.
Shimura
, T.
Sakakibara
, D.
Nishio-Hamane
, Y.
Karaki
, Y.
Takata
, M.
Matsunami
, R.
Eguchi
, M.
Taguchi
, A.
Chainani
, S.
Shin
, K.
Tamasaku
, Y.
Nishino
, M.
Yabashi
, T.
Ishikawa
, and S.
Nakatsuji
, “Quantum valence criticality in a correlated metal
,” Sci. Adv.
4
, eaao3547
(2018
).48.
S.
Suzuki
, K.
Takubo
, K.
Kuga
, W.
Higemoto
, T. U.
Ito
, T.
Tomita
, Y.
Shimura
, Y.
Matsumoto
, C.
Bareille
, H.
Wadati
, S.
Shin
, and S.
Nakatsuji
, “High temperature antiferromagnetism in Yb based heavy fermion systems proximate to a Kondo insulator
,” Phys. Rev. Res.
3
, 023140
(2021
).49.
S.
Nakatsuji
, K.
Kuga
, Y.
Machida
, T.
Tayama
, T.
Sakakibara
, Y.
Karaki
, H.
Ishimoto
, S.
Yonezawa
, Y.
Maeno
, E.
Pearson
, G. G.
Lonzarich
, L.
Balicas
, H.
Lee
, and Z.
Fisk
, “Superconductivity and quantum criticality in the heavy-fermion system β-YbAlB4
,” Nat. Phys.
4
, 603
(2008
).50.
Y.
Matsumoto
, S.
Nakatsuji
, K.
Kuga
, Y.
Karaki
, N.
Horie
, Y.
Shimura
, T.
Sakakibara
, A.
Nevidomskyy
, and P.
Coleman
, “Quantum criticality without tuning in the mixed valence compound β-YbAlB4
,” Science
331
, 316
(2011
).51.
T.
Tomita
, K.
Kuga
, Y.
Uwatoko
, P.
Coleman
, and S.
Nakatsuji
, “Strange metal without magnetic criticality
,” Science
349
, 506
(2015
).52.
T.
Willers
, F.
Strigari
, Z.
Hu
, V.
Sessi
, N. B.
Brookes
, E. D.
Bauer
, J. L.
Sarrao
, J. D.
Thompson
, A.
Tanaka
, S.
Wirth
, L. H.
Tjeng
, and A.
Severing
, “Correlation between ground state and orbital anisotropy in heavy fermion materials
,” Proc. Natl. Acad. Sci. U. S. A.
112
, 2384
–2388
(2015
).© 2021 Author(s). Published under an exclusive license by AIP Publishing.
2021
Author(s)
You do not currently have access to this content.
