Interfacial Engineering of Ferromagnetism in Epitaxial Manganite/Ruthenate Superlattices via Interlayer Chemical Doping
Interfacial Engineering of Ferromagnetism in Epitaxial Manganite/Ruthenate Superlattices via Interlayer Chemical Doping
复制标题
通过层间化学掺杂实现外延锰酸盐/钌酸盐超晶格中铁磁性的界面工程
DOI：
10.1021/acsami.8b22055
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Wenbin Wu
中科院分区：
文献类型：
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作者：
Da Lan;Binbin Chen;LiLi Qu;Feng Jin;Zhuang Guo;Liqiang Xu;Kexuan Zhang;Guanyin Gao;Feng Chen;Shaowei Jin;Lingfei Wang;Wenbin Wu
界面电荷转移和结构邻近效应是触发和调节钙钛矿氧化物异质结构众多功能的两条基本途径。然而，这两种界面效应在同一外延系统中的协同和竞争作用还没有完全被理解。在此，我们制备了一系列La0.67Ca0.33MnO_3/CaRuO_3超晶格，并在非磁性CaRuO_3中间层中引入了各种化学掺杂。我们发现，在CaRuO_3层中掺入钛、锶和镧可以有效地调节界面电荷转移和八面体旋转，从而调制超晶格的铁磁性。具体地说，B位钛掺杂耗尽了Ru4d能带，抑制了界面电荷转移，导致了铁磁居里温度(TC)的衰减。与之相反，A位的锶掺杂保持了相当大的电荷转移，同时抑制了八面体的旋转，从而促进了铁磁性，显著地提高了TCUP到291K。La的掺杂使CaRuO_3层中的巡游电子局域化，这既抑制了界面电荷转移，又抑制了铁磁性。观察到的有趣的界面磁性工程将为理解界面电荷转移和结构邻近对氧化物异质结构物理性质的集体效应铺平一条新的途径。
Interfacial charge transfer and structural proximity effects are the two essential routes to trigger and tune numerous functionalities of perovskite oxide heterostructures. However, the cooperation and competition of these two interfacial effects in one epitaxial system have not been fully understood. Herein, we fabricate a series of La0.67Ca0.33MnO3/CaRuO3superlattices and introduce various chemical doping in the nonmagnetic CaRuO3interlayers. We found that Ti, Sr, and La doping in the CaRuO3layer can effectively tune the interfacial charge transfer and octahedral rotation, thus modulating the ferromagnetism of the superlattices. Specifically, the B-site Ti doping depletes the Ru 4d band and suppresses the interfacial charge transfer, leading to a decay of ferromagnetic Curie temperature (TC). In contrast, the A-site Sr doping maintains a sizable charge transfer and meanwhile suppresses the octahedral rotation, which facilitates ferromagnetism and significantly enhances theTCup to 291 K. The La doping turns out to localize the itinerant electrons in the CaRuO3layer, which suppresses both the interfacial charge transfer and ferromagnetism. The observed intriguing interfacial engineering of magnetism would pave a new way to understand the collective effects of interfacial charge transfer and structural proximity on the physical properties of oxide heterostructures.