Interfacial Charge Engineering in Ferroelectric-Controlled Mott Transistors

Xuegang Chen; Xin Zhang; Mark A Koten; Hanghui Chen; Zhiyong Xiao; Le Zhang; Jeffrey E Shield; Peter A Dowben; Xia Hong

doi:10.1002/adma.201701385

Interfacial Charge Engineering in Ferroelectric-Controlled Mott Transistors

Adv Mater. 2017 Aug;29(31). doi: 10.1002/adma.201701385. Epub 2017 Jun 19.

Authors

Xuegang Chen¹, Xin Zhang¹, Mark A Koten², Hanghui Chen^{3

4

5

6}, Zhiyong Xiao¹, Le Zhang¹, Jeffrey E Shield², Peter A Dowben¹, Xia Hong¹

Affiliations

¹ Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE, 68588-0299, USA.
² Department of Mechanical and Materials Engineering & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE, 68588-0526, USA.
³ Department of Physics, Columbia University, New York, NY, 10027, USA.
⁴ New York University Shanghai, Shanghai, 200122, China.
⁵ NYU-ECNU Institute of Physics, New York University Shanghai, Shanghai, 200062, China.
⁶ Department of Physics, New York University, New York, NY, 10002, USA.

PMID: 28628278
DOI: 10.1002/adma.201701385

Abstract

Heteroepitaxial coupling at complex oxide interfaces presents a powerful tool for engineering the charge degree of freedom in strongly correlated materials, which can be utilized to achieve tailored functionalities that are inaccessible in the bulk form. Here, the charge-transfer effect between two strongly correlated oxides, Sm_0.5 Nd_0.5 NiO₃ (SNNO) and La_0.67 Sr_0.33 MnO₃ (LSMO), is exploited to realize a giant enhancement of the ferroelectric field effect in a prototype Mott field-effect transistor. By switching the polarization field of a ferroelectric Pb(Zr,Ti)O₃ (PZT) gate, nonvolatile resistance modulation in the Mott transistors with single-layer SNNO and bilayer SNNO/LSMO channels is induced. For the same channel thickness, the bilayer channels exhibit up to two orders of magnitude higher resistance-switching ratio at 300 K, which is attributed to the intricate interplay between the charge screening at the PZT/SNNO interface and the charge transfer at the SNNO/LSMO interface. X-ray absorption spectroscopy and X-ray photoelectron spectroscopy studies of SNNO/LSMO heterostructures reveal about 0.1 electron per 2D unit cell transferred between the interfacial Mn and Ni layers, which is corroborated by first-principles density functional theory calculations. The study points to an effective strategy to design functional complex oxide interfaces for developing high-performance nanoelectronic and spintronic applications.

Keywords: Mott insulators; charge transfer; complex oxide interfaces; ferroelectric field effect; strongly correlated oxides.