Charge‐transfer‐induced multivalent states with resultant emergent magnetism in transition‐metal oxide heterostructures

DOI: 10.1002/aelm.202000803

Authors: Wei Niu (Nanjing University of Posts and Telecommunications; Nanjing University) , Yue‐wen Fang (Tokyo Institute of Technology; University Shanghai; Nanjing University) , Xiaoqian Zhang (Nanjing University of Posts and Telecommunications) , Yakui Weng (Nanjing University of Posts and Telecommunications) , Yongda Chen (Nanjing University) , Hui Zhang (Beihang University) , Yulin Gan (Beijing National Laboratory for Condensed Matter and Institute of Physics, Chinese Academy of Sciences) , Xiao Yuan (Nanjing University) , Shengjie Zhang (Nanjing University of Posts and Telecommunications) , Jiabao Sun (Royal Holloway, University of London) , Yile Wang (Nanjing University of Posts and Telecommunications) , Lujun Wei (Nanjing University of Posts and Telecommunications) , Yongbing Xu (Nanjing University of Posts and Telecommunications; Nanjing University) , Xuefeng Wang (Nanjing University) , Wenqing Liu (Royal Holloway, University of London) , Yong Pu (Nanjing University of Posts and Telecommunications)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Advanced Electronic Materials , VOL 7

State: Published (Approved)
Published: November 2020
Diamond Proposal Number(s): 20748

Abstract: Transition‐metal oxide (TMO) heterostructures provide fertile grounds for creating and manipulating intriguing properties and functionalities. At the interface of TMO heterostructures, electronic reconstructions generally occur via charge transfer and lead to an extraordinary spectrum of emergent phenomena but unattainable in their bulk constituents. However, the basic mechanism of charge transfer at the interface is not fully determined or even understood in heterostructures, which may hide the underlying mechanisms and intriguing physics. Herein, an intrinsic charge transfer and resultant exotic ferromagnetism are unambiguously observed in the heterostructures between the nonmagnetic LaCoO3 (LCO) and SrTiO3 (STO). Combining element‐specific X‐ray absorption spectroscopy and atomic multiplet fitting, direct evidence of charge transfer‐induced multivalence of cobalt ions, interactions of which would contribute to the novel magnetism beyond the intuition, in concert with first‐principles density‐functional‐theory calculations, is demonstrated. Beyond LCO/STO system, a more broadly applicable principle for the heterostructures between 3d TMO and STO where charge transfer and resultant multivalence or conducting interfaces are coexistent is establish. This study represents an advance that the electronic reconstruction and the multiple electron configurations of 3d transition metal ions will constitute a powerful tool for the designs of functional materials and creations of unconventional physical properties.

Journal Keywords: charge transfer; magnetism; multivalent states; oxide heterostructures

Subject Areas: Materials, Physics


Instruments: I10-Beamline for Advanced Dichroism - scattering

Added On: 26/11/2020 09:08

Discipline Tags:

Hard condensed matter - electronic properties Physics Magnetism Materials Science

Technical Tags:

Spectroscopy Circular Dichroism (CD) X-ray Absorption Spectroscopy (XAS) X-ray Magnetic Circular Dichroism (XMCD)