TY - JOUR
T1 - Modulation of Manganite Nanofilm Properties Mediated by Strong Influence of Strontium Titanate Excitons
AU - Yin, Xinmao
AU - Tang, Chi Sin
AU - Majidi, Muhammad Aziz
AU - Ren, Peng
AU - Wang, Le
AU - Yang, Ping
AU - Diao, Caozheng
AU - Yu, Xiaojiang
AU - Breese, Mark B.H.
AU - Wee, Andrew T.S.
AU - Wang, Junling
AU - Rusydi, Andrivo
N1 - Funding Information:
This work is supported by the Singapore Ministry of Education (MOE2015-T2-2-065, MOE2015-T2-1-099, MOE2015-T2-2-147, and MOE2016-T2-1-054), the Singapore National Research Foundation under its Competitive Research Funding (NRF-CRP 8-2011-06 and NRF-CRP15-2015-01), NUS-YIA, FRCs (R-144-000-379-114 and R-144-000-368-112), and NUS Core Support C-380-003-003-001. We thank the Centre for Advanced 2D Materials at the National University of Singapore to provide the computing resource. The authors would also like to acknowledge the Singapore Synchrotron Light Source (SSLS) for providing the facility necessary for conducting the research. The Laboratory is a National Research Infrastructure under the National Research Foundation Singapore.
Publisher Copyright:
© Copyright 2017 American Chemical Society.
PY - 2018/10/17
Y1 - 2018/10/17
N2 - Hole-doped perovskite manganites have attracted much attention because of their unique optical, electronic, and magnetic properties induced by the interplay between spin, charge, orbital, and lattice degrees of freedom. Here, a comprehensive investigation of the optical, electronic, and magnetic properties of La 0.7 Sr 0.3 MnO 3 thin films on SrTiO 3 (LSMO/STO) and other substrates is conducted using a combination of temperature-dependent transport, spectroscopic ellipsometry, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism. A significant difference in the optical property of LSMO/STO that occurs even in thick (87.2 nm) LSMO/STO from that of LSMO on other substrates is discovered. Several excitonic features are observed in thin film nanostructure LSMO/STO at -4 eV, which could be attributed to the formation of anomalous charged excitonic complexes. On the basis of the spectral weight transfer analysis, anomalous excitonic effects from STO strengthen the electronic correlation in LSMO films. This results in the occurrence of optical spectral changes related to the intrinsic Mott-Hubbard properties in manganites. We find that while lattice strain from the substrate influences the optical properties of the LSMO thin films, the coexistence of strong electron-electron (e-e) and electron-hole (e-h) interactions which leads to the resonant excitonic effects from the substrate plays a much more significant role. Our result shows that the onset of anomalous excitonic dynamics in manganite oxides may potentially generate new approaches in manipulating exciton-based optoelectronic applications.
AB - Hole-doped perovskite manganites have attracted much attention because of their unique optical, electronic, and magnetic properties induced by the interplay between spin, charge, orbital, and lattice degrees of freedom. Here, a comprehensive investigation of the optical, electronic, and magnetic properties of La 0.7 Sr 0.3 MnO 3 thin films on SrTiO 3 (LSMO/STO) and other substrates is conducted using a combination of temperature-dependent transport, spectroscopic ellipsometry, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism. A significant difference in the optical property of LSMO/STO that occurs even in thick (87.2 nm) LSMO/STO from that of LSMO on other substrates is discovered. Several excitonic features are observed in thin film nanostructure LSMO/STO at -4 eV, which could be attributed to the formation of anomalous charged excitonic complexes. On the basis of the spectral weight transfer analysis, anomalous excitonic effects from STO strengthen the electronic correlation in LSMO films. This results in the occurrence of optical spectral changes related to the intrinsic Mott-Hubbard properties in manganites. We find that while lattice strain from the substrate influences the optical properties of the LSMO thin films, the coexistence of strong electron-electron (e-e) and electron-hole (e-h) interactions which leads to the resonant excitonic effects from the substrate plays a much more significant role. Our result shows that the onset of anomalous excitonic dynamics in manganite oxides may potentially generate new approaches in manipulating exciton-based optoelectronic applications.
KW - electron-electron and electron-hole interactions
KW - electronic and optical structures
KW - manganite thin film
KW - neutral and charged excitonic effects
KW - spectroscopic ellipsometry
UR - http://www.scopus.com/inward/record.url?scp=85054611891&partnerID=8YFLogxK
U2 - 10.1021/acsami.7b15347
DO - 10.1021/acsami.7b15347
M3 - Article
AN - SCOPUS:85054611891
SN - 1944-8244
VL - 10
SP - 35563
EP - 35570
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 41
ER -