Materials with exceptional magnetism and superconductivity usually conceive emergent physical phenomena. Here, we investigate the physical properties of the (Eu,La)FeAs₂ system with double magnetic sublattices. The parent EuFeAs₂ shows anisotropy-associated magnetic behaviors, such as Eu-related moment canting and exchange bias. Through La doping, the magnetic anisotropy is enhanced with ferromagnetism of Eu²⁺ realized in the overdoped region, and a special exchange bias of the superposed ferromagnetic/superconducting loop revealed in Eu_0.8La_0.2FeAs₂. Meanwhile, the Fe-related antiferromagnetism shows unusual robustness against La doping. Theoretical calculation and ⁵⁷Fe Mössbauer spectroscopy investigation reveal a doping-tunable dual itinerant/localized nature of the Fe-related antiferromagnetism. The coexistence of the Eu-related ferromagnetism, Fe-related robust antiferromagnetism, and superconductivity is further revealed in Eu_0.8La_0.2FeAs₂, providing a platform for further exploration of potential applications and emergent physics. Finally, an electronic phase diagram is established for (Eu,La)FeAs₂ with the whole superconducting dome adjacent to the Fe-related antiferromagnetic phase, which is of benefit for seeking underlying clues to high-temperature superconductivity.

具有特殊磁性和超导性的材料通常会产生涌现的物理现象。在这里，我们研究了具有双磁性亚晶格的 (Eu,La)FeAs ₂系统的物理性质。母体 EuFeAs ₂显示出与各向异性相关的磁行为，例如与 Eu 相关的矩倾斜和交换偏置。通过La掺杂，在过掺杂区域实现了Eu ^{2+ 的}铁磁性，并且在Eu _0.8 La _0.2 FeAs _{2 中}显示了叠加的铁磁/超导回路的特殊交换偏置，从而增强了磁各向异性。同时，与 Fe 相关的反铁磁性对 La 掺杂表现出不同寻常的鲁棒性。理论计算与⁵⁷Fe Mössbauer 光谱研究揭示了与 Fe 相关的反铁磁性的掺杂可调双重巡回/局部性质。Eu _0.8 La _0.2 FeAs ₂进一步揭示了Eu相关铁磁性、Fe相关强反铁磁性和超导性的共存，为进一步探索潜在应用和新兴物理学提供了平台。最后，建立了(Eu,La)FeAs ₂的电子相图，整个超导圆顶与与Fe 相关的反铁磁相相邻，这有利于寻找高温超导的潜在线索。