The experimental evidence of the exchange bias (EB) effect in epitaxial heterostructures of ferromagnetic La_0.67Sr_0.33MnO₃ (LSMO) and paramagnetic LaNiO₃ (LNO) grown on MgO(001) substrates is reported. The macroscopic magnetization measurements show a clear indication of EB in LNO/LSMO and LSMO/LNO/LSMO heterostructures. The strength of the exchange coupling rapidly reduces as the temperature is increased and almost vanishes above 50 K. Using spin dependent polarized neutron reflectometry (PNR) detailed depth dependent magnetization profiles of the heterostructures are investigated to understand the role of interface magnetism in the observed EB. PNR results establish the emergence of the interfacial ferromagnetic LNO layer of thickness ≈22–35 Å (≈6–9 unit cell) and magnetization ≈80 emu cc⁻¹ at the LNO/LSMO interface for T < 100 K. The PNR results also show both ferromagnetic and anti‐ferromagnetic coupling between the LSMO and interfacial LNO layers, which may be dependent on the stacking order. The emergence of ferromagnetism in the interfacial paramagnetic LNO layer with unexpected EB in these heterostructures suggests a promising platform toward the effective realization of magnetic devices.

中文翻译：

---

顺磁性/铁磁性氧化物异质结构中的新兴界面铁磁性和交换偏置效应

铁磁性La _0.67 Sr _0.33 MnO ₃（LSMO）和顺磁性LaNiO ₃外延异质结构中交换偏压（EB）效应的实验证据报道了在MgO（001）衬底上生长的（LNO）。宏观磁化测量结果清楚地表明了LNO / LSMO和LSMO / LNO / LSMO异质结构中的EB。随着温度的升高，交换耦合的强度迅速降低，并在50 K以上几乎消失。使用自旋相关的极化中子反射法（PNR），详细研究了异质结构的深度相关的磁化曲线，以了解界面磁在观测的EB中的作用。 。PNR结果确定了在T的LNO / LSMO界面处出现厚度为≈22–35Å（≈6–9晶胞）和磁化强度为≈80emu cc ^-1的界面铁磁LNO层的出现 <100K。PNR结果还显示了LSMO和界面LNO层之间的铁磁耦合和反铁磁耦合，这可能取决于堆叠顺序。在这些异质结构中具有意外的EB的顺磁性LNO界面中出现了铁磁性，这为有效实现磁性器件提供了一个有前途的平台。