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

• Published in: ACS applied materials & interfaces 2020-03, Vol.12 (10), p.12238-12245
• Main Authors: Mei, Chenguang, Lin, Zhu, Zhang, Ruixin, Xu, Chengchao, Huang, Haoliang, Dong, Yongqi, Meng, Miao, Gao, Ye, Zhang, Xi, Zhang, Qinghua, Gu, Lin, Yang, Huaixin, Tian, Huanfang, Li, Jianqi, Lu, Yalin, Zhang, Guangming, Zhao, Yonggang
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.9b18749

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 FeSe0.5Te0.5 (FST) films on FE Pb­(Mg1/3Nb2/3)0.7Ti0.3O3 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.