Growth of High-Quality Superconducting FeSe0.5Te0.5 Films on Pb(Mg1/3Nb2/3)0.7Ti0.3O3 and Electric-Field Modulation of Superconductivity

Chenguang Mei; Zhu Lin; Ruixin Zhang; Chengchao Xu; Haoliang Huang; Yongqi Dong; Miao Meng; Ye Gao; Xi Zhang; Qinghua Zhang; Lin Gu; Huaixin Yang; Huanfang Tian; Jianqi Li; Yalin Lu; Guangming Zhang; Yonggang Zhao

doi:10.1021/acsami.9b18749

Growth of High-Quality Superconducting FeSe_0.5Te_0.5 Films on Pb(Mg_1/3Nb_2/3)_0.7Ti_0.3O₃ and Electric-Field Modulation of Superconductivity

ACS Appl Mater Interfaces. 2020 Mar 11;12(10):12238-12245. doi: 10.1021/acsami.9b18749. Epub 2020 Feb 25.

Authors

Chenguang Mei^{1

2}, Zhu Lin^{1

2}, Ruixin Zhang³, Chengchao Xu³, Haoliang Huang⁴, Yongqi Dong⁴, Miao Meng^{1

2}, Ye Gao^{1

2}, Xi Zhang^{1

2}, Qinghua Zhang³, Lin Gu³, Huaixin Yang³, Huanfang Tian³, Jianqi Li³, Yalin Lu⁴, Guangming Zhang^{1

2}, Yonggang Zhao^{1

2}

Affiliations

¹ Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China.
² Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China.
³ Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
⁴ CAS Key Laboratory of Materials for Energy Conversion, Hefei National Laboratory for Physical Sciences at the Microscale & National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China.

PMID: 32052958
DOI: 10.1021/acsami.9b18749

Abstract

Heterostructures composed of superconductor and ferroelectrics (SC/FE) are very important for manipulating the superconducting property and applications. However, growth of high-quality superconducting iron chalcogenide films is challenging because of their volatility and FE substrate with rough surface and large lattice mismatch. Here, we report a two-step growth approach to get high-quality FeSe_0.5Te_0.5 (FST) films on FE Pb(Mg_1/3Nb_2/3)_0.7Ti_0.3O₃ with large lattice mismatch, which show superconductivity at only around 10 nm. Through a systematic study of structural and electric transport properties of samples with different thicknesses, a mechanism to grow high-quality FST is discovered. Moreover, electric-field-induced remarkable change of T_c (superconducting transition temperature) is demonstrated in a 20 nm FST film. This work paves the way to grow high-quality films which contain volatile element and have large lattice mismatch with the substrate. It is also helpful for manipulating the superconducting property in SC/FE heterostructures.

Keywords: FeSe0.5Te0.5; Pb(Mg1/3Nb2/3)0.7Ti0.3O3; electric-field modulation; thickness dependence; two-step method.