The authors analyze the x-ray photoelectron spectra of SrTiO3(100) (STO) substrates to clarify the electronic structure characteristics induced by a sputter–anneal procedure. The survey spectra, the valence band spectra, and the relevant core level spectra, i.e., Sr 3s, Sr 3p, Sr 3d, Sr 4s, Sr 4p, Ti 2p, Ti 3s, Ti 3p, O 1s, and O 2s along with their satellite structures, of both pristine and sputtered and annealed STO have been measured. A comparison of spectra reveals the appearance of new features in the Ti 2p spectra of sputtered and annealed STO, corresponding to Ti3+ states and gap states near the Fermi energy. The presence of Ti3+ states points to the formation of a two-dimensional electron system at the STO surface generated by Ar+ sputtering and annealing in vacuum. Furthermore, the sputter-annealed surface shows only minor carbon contamination as compared to that of the pristine substrate.
REFERENCES
1.
D.
Stornaiuolo
, D.
Massarotti
, R.
Di Capua
, P.
Lucignano
, G. P.
Pepe
, M.
Salluzzo
, and F.
Tafuri
, Phys. Rev. B
95
, 140502
(2017
). 2.
N.
Reyren
et al., Science
317
, 1196
(2007
). 3.
S.
Thiel
, G.
Hammerl
, A.
Schmehl
, C. W.
Schneider
, and J.
Mannhart
, Science
313
, 1942
(2006
). 4.
J. S.
Lee
, J.-S.
Lee
, Y. W.
Xie
, H. K.
Sato
, C.
Bell
, Y.
Hikita
, H. Y.
Hwang
, and C.-C.
Kao
, Nat. Mater.
12
, 703
(2013
). 5.
Ariando
et al., Nat. Commun.
2
, 188
(2011
). 6.
G.
Blamire
, J. L.
MacManus
, N. D.
Mathur
, and Z. H.
Barber
, Adv. Mater.
21
, 3827
(2009
). 7.
H. N.
Lee
, H. M.
Christen
, M. F.
Chisholm
, C. M.
Rouleau
, and D. H.
Lowndes
, Nature
433
, 395
(2005
). 8.
A.
Ohtomo
and H.
Hwang
, Nature
427
, 423
(2004
). 9.
A. D.
Caviglia
et al., Nature
456
, 624
(2008
). 10.
L.
Li
, C.
Richter
, J.
Mannhart
, and R. C.
Ashoori
, Nat. Phys.
7
, 762
(2011
). 11.
M. B.
Shalom
, M.
Sachs
, D.
Rakhmilevitch
, A.
Palevski
, and Y.
Dagan
, Phys. Rev. Lett.
104
, 126802
(2010
). 12.
A.
Biswas
, C. H.
Yang
, R.
Ramesh
, and Y. H.
Jeong
, Prog. Surf. Sci.
92
, 117
(2017
). 13.
C.
Baeumer
, C.
Xu
, F.
Gunkel
, N.
Raab
, R. A.
Heinen
, A.
Koehl
, and R.
Dittmann
, Sci. Rep.
5
, 11829
(2015
). 14.
D.
Hrabovsky
, B.
Berini
, A.
Fouchet
, D.
Aureau
, N.
Keller
, A.
Etcheberry
, and Y.
Dumont
, Appl. Surf. Sci.
367
, 307
(2016
). 15.
B.
Psiuk
, J.
Szade
, M.
Pilch
, and K.
Szot
, Vacuum
83
, S69
(2009
). 16.
L.
Sygellou
, H.
Tielens
, C.
Adelmann
, and S.
Ladas
, Microelectron. Eng.
90
, 138
(2012
). 17.
B.
Psiuk
, J.
Szade
, H.
Haselier
, M.
Mlynarczyk
, R.
Waser
, and K.
Szot
, Appl. Phys. A
89
, 451
(2007
). 18.
P. A.
van der Heide
, Q. D.
Jiang
, Y. S.
Kim
, and J. W.
Rabalais
, Surf. Sci.
473
, 59
(2001
). 19.
R. P.
Vasquez
, Surf. Sci. Spectra
1
, 129
(1992
). 20.
R. T.
Haasch
, E.
Breckenfeld
, and L. W.
Martin
, Surf. Sci. Spectra
21
, 87
(2014
). 21.
B.
Cord
and R.
Courths
, Surf. Sci.
162
, 34
(1985
). 22.
N.
Bickel
, G.
Schmidt
, K.
Heinz
, and K.
Müller
, Phys. Rev. Lett.
62
, 2010
(1989
). 23.
K. S.
Kim
and N.
Winograd
, Chem. Phys. Lett.
31
, 312
(1975
). 24.
B. V.
Cris
, Handbook of Monochromatic XPS Spectra: The Elements of Native Oxides
(Wiley
, Chichester
, 2000
), p. 548
.25.
B.
Mayer
, S.
Mähl
, and M.
Neumann
, Z. Phys. B
101
, 85
(1996
). 26.
S. M.
Walker
et al., Adv. Mater.
27
, 3894
(2015
). 27.
28.
B.
Bharti
, S.
Kumar
, H.-N.
Lee
, and R.
Kumar
, Sci. Rep.
6
, 32355
(2016
). 29.
J.
Jun
, J.-H.
Shin
, and M.
Dhayal
, Appl. Surf. Sci.
252
, 3871
(2006
). 30.
Z. Q.
Zheng
and X. P.
Zhou
, J. Am. Ceram. Soc.
96
, 3504
(2013
). 31.
B.
Santara
, P. K.
Giri
, K.
Imakita
, and M.
Fujii
, Nanoscale
5
, 5476
(2013
). 32.
K. A.
Bogle
, M. N.
Bachhav
, M. S.
Deo
, N.
Valanoor
, and S. B.
Ogale
, Appl. Phys. Lett.
95
, 203502
(2009
). 33.
J.
Zhuang
, S.
Weng
, W.
Dai
, P.
Liu
, and Q.
Liu
, J. Phys. Chem. C
116
, 25354
(2012
). 34.
W.
Meevasana
, P. D. C.
King
, R. H.
He
, S.-K.
Mo
, M.
Hashimoto
, A.
Tamai
, P.
Songsiriritthigul
, F.
Baumberger
, and Z.-X.
Shen
, Nat. Mater.
10
, 114
(2011
). 35.
L.
Rimai
and G. A.
deMars
, Phys. Rev.
127
, 702
(1962
). 36.
K. A.
Muller
, Phys. Rev. B
19
, 3593
(1979
). 37.
K. A.
Muller
, W.
Berlinger
, and J. C.
Slonczewski
, Phys. Rev. Lett.
25
, 734
(1970
). 38.
H.
Uwe
and T.
Sakudo
, Phys. Rev. B
13
, 271
(1976
). 39.
W. J.
Burke
and R. J.
Pressley
, Solid State Commun.
9
, 191
(1971
). 40.
R. W.
Wyckoff
, The Structure of Crystals
(The Chemical Catalog Company, Inc.
, New York
, 1935
).41.
H. Y.
Hwang
, Y.
Iwasa
, M.
Kawasaki
, B.
Keimer
, N.
Nagaosa
, and Y.
Tokura
, Nat. Mater.
11
, 103
(2012
). 42.
A. P.
Ramirez
, Science
315
, 1377
(2007
). 43.
M.
Lorenz
et al., J. Phys. D: Appl. Phys.
49
, 433001
(2016
). 44.
P.
Ngabonziza
et al., Phys. Rev. B
92
, 035405
(2015
). 45.
C. X.
Quintela
et al., APL Mater.
5
, 096103
(2017
). 46.
Y.
Nakazawa
, M.
Uchida
, S.
Nishihaya
, M.
Kriener
, Y.
Kozuka
, Y.
Taguchi
, and M.
Kawasaki
, Sci. Rep.
8
, 2244
(2018
). 47.
P.
Ngabonziza
, M. P.
Stehno
, H.
Myoren
, V. A.
Neumann
, G.
Koster
, and A.
Brinkman
, Adv. Electron. Mater.
2
, 1600157
(2016
). 48.
Z. S.
Popovic
, S.
Satpathy
, and R. M.
Martin
, Phys. Rev. Lett.
101
, 256801
(2008
). 49.
M.
Sing
et al., Phys. Rev. Lett.
102
, 176805
(2009
). 50.
P. R.
Willmott
et al., Phys. Rev. Lett.
99
, 155502
(2007
). 51.
M.
Schmid
, H.-P.
Steinrück
, and J. M.
Gottfried
, Surf. Interface Anal.
46
, 505
(2014
). © 2018 Author(s).
2018
Author(s)
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