Magnetic exchange couplings among perovskite manganese oxide heterostructures (typified by SrRuO₃/La_0.3Sr_0.7MnO₃) have been widely studied as potential components of metal-oxide spintronic devices, while bi-layered manganite related magnetic coupling phenomenon has never been reported. In this work, we find an obvious enhancement of coercivity in Fe/La_2−2xSr_1+2xMn₂O₇ (x=0.35, B-LSMO) starting at the transition temperature of B-LSMO single crystal. Systematic analysis on the temperature and external field evolution of magnetization reversal behavior reveals the emergence of antiferromagnetic interfacial exchange coupling between Fe and B-LSMO. Our results shed new light on tuning of magnetic property on layered oxide interface and designing novel spintronic devices.

钙钛矿型锰氧化物异质结构（以SrRuO ₃ / La _0.3 Sr _0.7 MnO ₃为代表）之间的磁交换耦合已被广泛研究为金属氧化物自旋电子器件的潜在组分，而从未报道过与双层锰有关的磁耦合现象。在这项工作中，我们发现Fe / La _2−2x Sr _{1 + 2x} Mn ₂ O ₇的矫顽力明显提高。（x = 0.35，B-LSMO）从B-LSMO单晶的转变温度开始。对磁化反转行为的温度和外场演化的系统分析揭示了Fe与B-LSMO之间反铁磁界面交换耦合的出现。我们的研究结果为调整层状氧化物界面上的磁性和设计新型自旋电子器件提供了新的思路。