State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
Small. 2017 May;13(18). doi: 10.1002/smll.201700107. Epub 2017 Mar 10.
Interface enhanced magnetism attracts much attention due to its potential use in exploring novel structure devices. Nevertheless, the magnetic behavior at interfaces has not been quantitatively determined. In this study, abnormal magnetic moment reduction is observed in La Sr MnO (LSMO)/BiFeO (BFO) superlattices, which is induced by ferromagnetic (FM)/antiferromagnetic (AFM) coupling in the interface. With reduced repetition of the superlattice's unit cell [(LSMO) /(BFO) ] (n = 1, 2, 5, 10) on a SrTiO substrate, magnetic moment reduction from 25.5 emu cc ([(LSMO) /(BFO) ] ) to 1.5 emu cc ([(LSMO) /(BFO) ] ) is obtained. Ab initio simulations show that due to the different magnetic domain formation energies, the magnetic moment orientation tends to be paramagnetic in the FM/AFM interface. The work focuses on the magnetic domain formation energy and provides a pathway to construct artificial heterostructures that can be an effective way to tune the magnetic moment orientation and control the magnetization of ultrathin films.
界面增强的磁性由于其在探索新型结构器件中的潜在应用而受到广泛关注。然而，界面处的磁行为尚未被定量确定。在这项研究中，观察到 La Sr MnO (LSMO)/BiFeO (BFO) 超晶格中存在异常磁矩降低，这是由界面处的铁磁 (FM)/反铁磁 (AFM) 耦合引起的。在 SrTiO 衬底上减少超晶格单元的重复次数 [(LSMO)/(BFO)] (n = 1, 2, 5, 10)，从 25.5 emu cc ([(LSMO)/(BFO)] ) 获得到 1.5 emu cc ([(LSMO)/(BFO)] ) 的磁矩降低。从头算模拟表明，由于不同的磁畴形成能，FM/AFM 界面处的磁矩取向趋于顺磁。这项工作重点研究了磁畴形成能，并提供了一种构建人工异质结构的途径，这可能是一种有效调节磁矩取向和控制超薄薄膜磁化的方法。
