Interfacial Spin Glass State and Exchange Bias in the Epitaxial La0.7Sr0.3MnO3/LaNiO3 Bilayer

Guo-Wei Zhou; Xiao-Fen Guan; Yu-Hao Bai; Zhi-Yong Quan; Feng-Xian Jiang; Xiao-Hong Xu

doi:10.1186/s11671-017-2110-0

Interfacial Spin Glass State and Exchange Bias in the Epitaxial La_0.7Sr_0.3MnO₃/LaNiO₃ Bilayer

Nanoscale Res Lett. 2017 Dec;12(1):330. doi: 10.1186/s11671-017-2110-0. Epub 2017 May 4.

Authors

Guo-Wei Zhou^{1

2}, Xiao-Fen Guan¹, Yu-Hao Bai^{1

3}, Zhi-Yong Quan^{1

2}, Feng-Xian Jiang^{1

2}, Xiao-Hong Xu^{4

5}

Affiliations

¹ School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University, Linfen, 041004, People's Republic of China.
² Research Institute of Materials Science, Shanxi Normal University, Linfen, 041004, China.
³ School of Physics and Electronic Information, Shanxi Normal University, Linfen, 041004, People's Republic of China.
⁴ School of Chemistry and Materials Science, Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University, Linfen, 041004, People's Republic of China. xuxh@dns.sxnu.edu.cn.
⁵ Research Institute of Materials Science, Shanxi Normal University, Linfen, 041004, China. xuxh@dns.sxnu.edu.cn.

Abstract

We study the magnetic properties of an epitaxial growth bilayer composed of ferromagnetic La_0.7Sr_0.3MnO₃ (LSMO) and paramagnetic LaNiO₃ (LNO) on SrTiO₃ (STO) substrates. We find that the stack order of the bilayer heterostructure plays a key role in the interfacial coupling strength, and the coupling at the LSMO(top)/LNO(bottom) interface is much stronger than that at the LNO(top)/LSMO(bottom). Moreover, a strong spin glass state has been observed at the LSMO/LNO interface, which is further confirmed by two facts: first, that the dependence of the irreversible temperature on the cooling magnetic field follows the Almeida-Thouless line and, second, that the relaxation of the thermal remnant magnetization can be fitted by a stretched exponential function. Interestingly, we also find an exchange bias effect at the LSMO/LNO bilayer below the spin glass freezing temperature, indicating that the exchange bias is strongly correlated with the spin glass state at its interface.

Keywords: Exchange bias; Interfaces; Magnetic materials; Spin glass state; Stack order.