title: Zero Thermal Expansion and Semiconducting Properties in PbTiO3-Bi(Co, Ti)O3Ferroelectric Solid Solutions.
abstract: Zero thermal expansion (ZTE) behavior is rare but important for both fundamental studies and practical applications of functional materials. Until now, most available ZTE materials are either electrical insulating oxides or conductive metallic compounds. Very few ZTE materials exhibit the semiconductor feature. Here we report a ZTE in a semiconducting ferroelectric of 0.6PbTiO3-0.4Bi(Co0.55Ti0.45)O3-δ. Its unit cell volume exhibits a negligible change over a broad temperature range from room temperature to 500 °C. The ZTE is supposed to be correlated with the spontaneous volume ferroelectronstriction. Intriguingly, the present ZTE material also exhibits the semiconducting characteristic accompanied by negative temperature coefficient of resistance. The mechanism of electric conduction is attributed to the electronic hopping from one ion (Ti3+) to another (Ti4+). The semiconductor nature has also been confirmed by the noticeable visible-light absorption with the relatively lower band gap (Eg) value of 1.5 eV, while the ferroelectric property can be well-maintained with large polarization. The first-principles calculations reveal that the drastically narrowed Egis related to the Co-Ti substitution. The present multifunctional material containing ZTE, semiconducting, and ferroelectric properties is suggested to enable new applications such as the substrate for solar conversion devices.
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Jun
authors.identifier: http://orcid.org/0000-0002-8693-2508
authors.initials: J
authors.lastname: Chen
authors.affiliation: BCCRD, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Xingxing
authors.initials: X
authors.lastname: Jiang
authors.affiliation: BCCRD, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Zheshuai
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Linxing
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Longlong
authors.initials: L
authors.lastname: Fan
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Yangchun
authors.initials: Y
authors.lastname: Rong
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ren
authors.affiliation: College of Materials Science and Engineering, Guilin University of Technology , Guilin 541004, People's Republic of China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Kuang
authors.affiliation: Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
authors.forename: Xianran
authors.identifier: http://orcid.org/0000-0003-0704-8886
authors.initials: X
authors.lastname: Xing