Influence of chemical composition and crystallographic orientation on the interfacial magnetism in BiFeO3/La1-xSrxMnO3 superlattices
Influence of chemical composition and crystallographic orientation on the interfacial magnetism in BiFeO3/La1-xSrxMnO3 superlattices
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DOI：
10.1103/physrevmaterials.2.114404
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发表时间：
2018-11-13
影响因子：
3.4
通讯作者：
Fitzsimmons, Michael R.
中科院分区：
文献类型：
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作者：
Guo, Er-Jia;Roldan, Manuel A.;Fitzsimmons, Michael R.
多铁性BiFeO3 （BFO）和铁磁性La1-xSrxMnO3 （LSMO）之间界面的独特磁性的出现，为利用电场控制纳米异质结构的磁性提供了机会。本文研究了BFO/LSMO超晶格的化学组成和晶体取向对界面磁性的影响。结果表明，随着LSMO层饱和磁化强度的增加，BFO层的感应净磁矩单调增加。对于(100)-BFO/LSMO （x = 0.2）超晶格，诱导矩达到了创纪录的2.8 mu(B)/Fe。当LSMO为反铁磁体时，在(100)-BFO/LSMO界面未观察到界面磁化。与（100）取向超晶格相比，(111)-BFO层中没有观察到诱导力矩。我们的研究结果表明，界面结构重建可能不是BFO层中净弯矩增强的充分条件。相反，在(100)-BFO中提出了由界面交换耦合引起的自旋倾斜，但在(111)-BFO中没有提出，导致（100）取向界面处的净磁化强度很大。这项工作进一步证明了在名义上的反铁磁体中，跨异质界面的交换耦合对自旋倾斜的重要性，为控制人造氧化物异质结构的磁性提供了一条途径。
The emergence of magnetism unique to the interface between the multiferroic BiFeO3 (BFO) and ferromagnetic La1-xSrxMnO3 (LSMO) offers an opportunity to control magnetism in nanoscale heterostructures with electric fields. In this paper, we investigate the influence of chemical composition and crystallographic orientation on the interfacial magnetism of BFO/LSMO superlattices. Our results reveal that the induced net magnetic moment in the BFO layers increases monotonically with increasing saturation magnetization of the LSMO layers. For the (100)-BFO/LSMO (x = 0.2) superlattice, the induced moment reaches a record high value of similar to 2.8 mu(B)/Fe. No interfacial magnetization is observed at the (100)-BFO/LSMO interface when LSMO is an antiferromagnet. In contrast to (100)-oriented superlattices, no induced moment is observed in (111)-BFO layers. Our results suggest the interfacial structural reconstruction may not be a sufficient condition for the enhanced net moment in BFO layer. Instead, spin canting induced by interfacial exchange coupling is proposed in the (100)-but not in the (111)-BFO, leading to the large net magnetization at the (100)-oriented interface. This work further demonstrates the importance of exchange coupling across heterointerfaces for spin canting in nominally antiferromagnets, providing a pathway to control the magnetic properties of artificial oxide heterostructures.