Zhou Guo-Wei, Guan Xiao-Fen, Bai Yu-Hao, Quan Zhi-Yong, Jiang Feng-Xian, Xu Xiao-Hong
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.
Research Institute of Materials Science, Shanxi Normal University, Linfen, 041004, China.
Nanoscale Res Lett. 2017 Dec;12(1):330. doi: 10.1186/s11671-017-2110-0. Epub 2017 May 4.
We study the magnetic properties of an epitaxial growth bilayer composed of ferromagnetic LaSrMnO (LSMO) and paramagnetic LaNiO (LNO) on SrTiO (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.
我们研究了在SrTiO（STO）衬底上由铁磁体LaSrMnO（LSMO）和顺磁体LaNiO（LNO）组成的外延生长双层的磁性。我们发现双层异质结构的堆叠顺序在界面耦合强度中起关键作用，并且LSMO（顶部）/LNO（底部）界面处的耦合比LNO（顶部）/LSMO（底部）处的耦合要强得多。此外，在LSMO/LNO界面处观察到了强自旋玻璃态，这通过两个事实得到进一步证实：第一，不可逆温度对冷却磁场的依赖性遵循阿尔梅达 - 索利斯线；第二，热剩余磁化强度的弛豫可以用拉伸指数函数拟合。有趣的是，我们还发现在自旋玻璃冻结温度以下的LSMO/LNO双层中存在交换偏置效应，这表明交换偏置与其界面处的自旋玻璃态密切相关。
