Half-metallic ferromagnets (HMFs) that possess intriguing physical properties with completely spin-polarized current are key candidates for high-efficiency spintronic devices. However, HMFs that could simultaneously have high Curie temperature (T_c), wide half-metallic gap (Δ_HM), and large bulk magnetocrystalline anisotropy energy (MAE) are very rare, which significantly restrict their room-temperature (RT) applications. In this article, through materials screening in layered halide double perovskites (LHDPs), we have theoretically identified that Cs₄FePb₂Cl₁₂, which has good crystallographic, dynamic and thermal stabilities, possesses an intrinsic half-metallic ground-state with a high T_c ~ 450 K. Interestingly, the long-range ferromagnetic ordering in bulk Cs₄FePb₂Cl₁₂ is contributed by the strong super-superexchange interactions between the neighboring Fe d orbitals mediated by different anionic Cl p orbitals. The high T_c of layered Cs₄FePb₂Cl₁₂ can be well maintained even in the monolayer limitation, i.e., T_c ~ 370 K for Cs₄FePb₂Cl₁₂ monolayer, which is critical for nanoscale device applications. Moreover, both bulk and monolayer Cs₄FePb₂Cl₁₂ can exhibit wide Δ_HM ~ 0.55 eV and large MAE >320 μeV/Fe, comparable to that of the best HMFs reported in the literature. Our findings can significantly extend the potentials of LHDPs for high-temperature spintronic applications.

具有引人入胜的物理特性且具有完全自旋极化电流的半金属铁磁体（HMF）是高效自旋电子器件的关键候选人。但是，同时具有高居里温度（T _c），宽半金属间隙（_ΔHM）和大块体磁晶各向异性能（MAE）的HMF非常罕见，这极大地限制了其室温（RT）应用。在本文中，通过在层状卤化双钙钛矿中进行材料筛选，我们从理论上确定了具有良好晶体学，动态和热稳定性的Cs ₄ FePb ₂ Cl ₁₂具有高固有的半金属基态。Ť _Ç  〜450 K.有趣的是，远距离散装铯铁磁有序₄ FePb ₂氯₁₂是由相邻的铁之间的强烈超超交换相互作用贡献d由不同的阴离子氯介导的轨道p轨道。高Ť _Ç分层Cs的₄ FePb ₂氯₁₂甚至可以在单层限制地保持良好，即Ť _Ç  〜370 K中铯₄ FePb ₂氯₁₂单层，这对于纳米级设备的应用至关重要。此外，散装和单层铯₄ FePb ₂氯₁₂可以表现出宽的Δ _HM  〜0.55 eV和大MAE> 320μeV/铁，比得上最好HMFS的文献报道。我们的发现可以显着扩展LHDP在高温自旋电子学应用中的潜力。