Antiferromagnetic Order in the Rare-Earth Halide Perovskites CsEuBr3 and CsEuCl3

Bulk CsEuBr3 and CsEuCl3 are experimentally shown to be magnetic semiconductors that order antiferromagnetically at Néel temperatures of 2.0 K and 1.0 K, respectively. Given that nanoparticles and thin films of CsEuCl3 have been reported to order ferromagnetically at a similar temperature, our observation of antiferromagnetic ordering in CsEuBr3 and CsEuCl3 expands the possible applications of halide perovskites to now include spintronic devices where both ferromagnetic and antiferromagnetic devices can be fabricated from a single material. The conclusion that CsEuCl3 can be used as a switchable magnetic material is also supported by our density-functional theory calculations.

块体CsEuBr3与CsEuCl3经实验证实为磁性半导体，二者分别在2.0 K与1.0 K的奈耳温度（Néel temperature）下发生反铁磁有序。已有研究报道，CsEuCl3的纳米颗粒与薄膜可在相近温度下呈现铁磁有序；我们在CsEuBr3与CsEuCl3中观测到的反铁磁有序现象，将卤化物钙钛矿（halide perovskites）的潜在应用范畴拓展至自旋电子器件领域，如今可通过单一材料同时制备铁磁与反铁磁器件。我们的密度泛函理论（density-functional theory）计算同样佐证了"CsEuCl3可作为可切换磁性材料"这一结论。