TY - JOUR
T1 - Metallic interfaces in a CaTiO3 / LaTiO3 superlattice
AU - Xiao, Shaozhu
AU - Wen, Fangdi
AU - Liu, Xiaoran
AU - Kareev, M.
AU - Zhang, Ruyi
AU - Song, Yang
AU - Pei, Yujuan
AU - Bi, Jiachang
AU - He, Shaolong
AU - Lu, Jiangbo
AU - Cao, Yanwei
AU - Chakhalian, J.
N1 - Funding Information:
This work is supported by the National Natural Science Foundation of China (Grant No. 11874058), the Pioneer Hundred Talents Program of the Chinese Academy of Sciences, the Ningbo 3315 Innovation Team, and the Ningbo Science and Technology Bureau (Grant No. 2018B10060). J.C. and X.L. acknowledge support from the Gordon and Betty Moore Foundation EPiQS Initiative through Grant No. GBMF4534. F.W. was supported by the Claud Lovelace Graduate Fellowship.
Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/10/22
Y1 - 2020/10/22
N2 - Apart from a handful of exceptions, all known complex oxide two-dimensional electron gases (2DEGs) are formed in SrTiO3-based heterostructures, and microscopic information about non-SrTiO3 2DEGs systems is scarce. Here, we report on the realization of metallic conductance in a CaTiO3-based system, CaTiO3/LaTiO3 superlattices, epitaxially grown in a layer-by-layer way on a NdGaO3(110) substrate by pulsed laser deposition. The high quality of the crystal and electronic structures is characterized by in situ reflection high-energy electron diffraction, x-ray diffraction, scanning transmission electron microscopy, and x-ray photoemission spectroscopy. Electrical transport confirms the formation of metallic interfaces in the CaTiO3/LaTiO3 superlattice. In addition, Hall measurements reveal that in the CaTiO3/LaTiO3 superlattice the roomerature carrier mobility is nearly three times higher than that of the CaTiO3/YTiO3 superlattice, implying the importance of TiO6 octahedral tilts and rotations on the carrier mobility of a 2DEG. Since doped CaTiO3 is an A-site polar metal, our results provide a materials system for designing synthetic two-dimensional polar metals.
AB - Apart from a handful of exceptions, all known complex oxide two-dimensional electron gases (2DEGs) are formed in SrTiO3-based heterostructures, and microscopic information about non-SrTiO3 2DEGs systems is scarce. Here, we report on the realization of metallic conductance in a CaTiO3-based system, CaTiO3/LaTiO3 superlattices, epitaxially grown in a layer-by-layer way on a NdGaO3(110) substrate by pulsed laser deposition. The high quality of the crystal and electronic structures is characterized by in situ reflection high-energy electron diffraction, x-ray diffraction, scanning transmission electron microscopy, and x-ray photoemission spectroscopy. Electrical transport confirms the formation of metallic interfaces in the CaTiO3/LaTiO3 superlattice. In addition, Hall measurements reveal that in the CaTiO3/LaTiO3 superlattice the roomerature carrier mobility is nearly three times higher than that of the CaTiO3/YTiO3 superlattice, implying the importance of TiO6 octahedral tilts and rotations on the carrier mobility of a 2DEG. Since doped CaTiO3 is an A-site polar metal, our results provide a materials system for designing synthetic two-dimensional polar metals.
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U2 - 10.1103/PhysRevMaterials.4.104008
DO - 10.1103/PhysRevMaterials.4.104008
M3 - Article
AN - SCOPUS:85095458724
SN - 2475-9953
VL - 4
JO - Physical Review Materials
JF - Physical Review Materials
IS - 10
M1 - 104008
ER -