title: Robust Interfacial Exchange Bias and Metal-Insulator Transition Influenced by the LaNiO3Layer Thickness in La0.7Sr0.3MnO3/LaNiO3Superlattices.
abstract: Artificial heterostructures based on LaNiO3(LNO) have been widely investigated with the aim to realize the insulating antiferromagnetic state of LNO. In this work, we grew [(La0.7Sr0.3MnO3)5-(LaNiO3)n]12superlattices on (001)-oriented SrTiO3substrates by pulsed laser deposition and observed an unexpected exchange bias effect in field-cooled hysteresis loops. Through X-ray absorption spectroscopy and magnetic circular dichroism experiments, we found that the charge transfer at the interfacial Mn and Ni ions can induce a localized magnetic moment. A remarkable increase of exchange bias field and a transition from metal to insulator were simultaneously observed upon decreasing the thickness of the LNO layer, indicating the antiferromagnetic insulator state in 2 unit cells LNO ultrathin layers. The robust exchange bias of 745 Oe in the superlattice is caused by an interfacial localized magnetic moment and an antiferromagnetic state in the ultrathin LNO layer, pinning the ferromagnetic La0.7Sr0.3MnO3layers together. Our results demonstrate that artificial interface engineering is a useful method to realize novel magnetic and transport properties.
authors.affiliation: School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University , Linfen 041004, China.|Research Institute of Materials Science, Shanxi Normal University , Linfen 041004, China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Song
authors.affiliation: School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University , Linfen 041004, China.|Research Institute of Materials Science, Shanxi Normal University , Linfen 041004, China.
authors.forename: Yuhao
authors.initials: Y
authors.lastname: Bai
authors.affiliation: School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University , Linfen 041004, China.|Research Institute of Materials Science, Shanxi Normal University , Linfen 041004, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Quan
authors.affiliation: School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University , Linfen 041004, China.|Research Institute of Materials Science, Shanxi Normal University , Linfen 041004, China.
authors.forename: Fengxian
authors.initials: F
authors.lastname: Jiang
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York , York YO10 5DD, U.K.|Department of Electronic Engineering, Royal Holloway, University of London , Egham, Surrey TW20 0EX, U.K.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York , York YO10 5DD, U.K.
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Harwell Science and Innovation Campus, Diamond Light Source , Didcot, Oxfordshire OX11 0DE, U.K.
authors.forename: Sarnjeet S
authors.initials: SS
authors.lastname: Dhesi
authors.affiliation: School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University , Linfen 041004, China.|Research Institute of Materials Science, Shanxi Normal University , Linfen 041004, China.
authors.forename: Xiaohong
authors.identifier: http://orcid.org/0000-0001-7588-4793
authors.initials: X
authors.lastname: Xu
keywords: LNO thickness; charge transfer; exchange bias; metal−insulator transition; superlattices