Interface-induced magnetic polar metal phase in complex oxides

Meng Meng; Zhen Wang; Aafreen Fathima; Saurabh Ghosh; Mohammad Saghayezhian; Joel Taylor; Rongying Jin; Yimei Zhu; Sokrates T Pantelides; Jiandi Zhang; E W Plummer; Hangwen Guo

doi:10.1038/s41467-019-13270-7

Interface-induced magnetic polar metal phase in complex oxides

Nat Commun. 2019 Nov 20;10(1):5248. doi: 10.1038/s41467-019-13270-7.

Authors

Meng Meng¹, Zhen Wang^{1

2}, Aafreen Fathima³, Saurabh Ghosh^{4

5

6}, Mohammad Saghayezhian¹, Joel Taylor¹, Rongying Jin¹, Yimei Zhu², Sokrates T Pantelides^{7

8}, Jiandi Zhang¹, E W Plummer⁹, Hangwen Guo¹⁰

Affiliations

¹ Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA.
² Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.
³ Department of Physics & Nanotechnology and SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, 603203, Tamil Nadu, India.
⁴ Department of Physics & Nanotechnology and SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, 603203, Tamil Nadu, India. saurabhghosh2802@gmail.com.
⁵ Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee, 37235, USA. saurabhghosh2802@gmail.com.
⁶ Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA. saurabhghosh2802@gmail.com.
⁷ Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee, 37235, USA.
⁸ Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA.
⁹ Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA. wplummer@phys.lsu.edu.
¹⁰ Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA. hangwenguo@fudan.edu.cn.

Abstract

Polar metals are commonly defined as metals with polar structural distortions. Strict symmetry restrictions make them an extremely rare breed as the structural constraints favor insulating over metallic phase. Moreover, no polar metals are known to be magnetic. Here we report on the realization of a magnetic polar metal phase in a BaTiO₃/SrRuO₃/BaTiO₃ heterostructure. Electron microscopy reveals polar lattice distortions in three-unit-cells thick SrRuO₃ between BaTiO₃ layers. Electrical transport and magnetization measurements reveal that this heterostructure possesses a metallic phase with high conductivity and ferromagnetic ordering with high saturation moment. The high conductivity in the SrRuO₃ layer can be attributed to the effect of electrostatic carrier accumulation induced by the BaTiO₃ layers. Density-functional-theory calculations provide insights into the origin of the observed properties of the thin SrRuO₃ film. The present results pave a way to design materials with desired functionalities at oxide interfaces.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.