Orthogonal interlayer coupling in an all-antiferromagnetic junction

• Published in: Nature communications Vol. 13; no. 1; p. 3723
• Main Authors: Zhou, Yongjian, Liao, Liyang, Guo, Tingwen, Bai, Hua, Zhao, Mingkun, Wan, Caihua, Huang, Lin, Han, Lei, Qiao, Leilei, You, Yunfeng, Chen, Chong, Chen, Ruyi, Zhou, Zhiyuan, Han, Xiufeng, Pan, Feng, Song, Cheng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 28.06.2022; Nature Publishing Group UK; Nature Portfolio
• Subjects: Antiferromagnetism; Chromium oxides; Couplings; Domain walls; Ferric oxide; Ferromagnetism; Interlayers; Magnetism; Room temperature; Sandwich structures
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-31531-w

Abstract In conventional ferromagnet/spacer/ferromagnet sandwiches, noncollinear couplings are commonly absent because of the low coupling energy and strong magnetization. For antiferromagnets (AFM), the small net moment can embody a low coupling energy as a sizable coupling field, however, such AFM sandwich structures have been scarcely explored. Here we demonstrate orthogonal interlayer coupling at room temperature in an all-antiferromagnetic junction Fe 2 O 3 /Cr 2 O 3 /Fe 2 O 3 , where the Néel vectors in the top and bottom Fe 2 O 3 layers are strongly orthogonally coupled and the coupling strength is significantly affected by the thickness of the antiferromagnetic Cr 2 O 3 spacer. From the energy and symmetry analysis, the direct coupling via uniform magnetic ordering in Cr 2 O 3 spacer in our junction is excluded. The coupling is proposed to be mediated by the non-uniform domain wall state in the spacer. The strong long-range coupling in an antiferromagnetic junction provides an unexplored approach for designing antiferromagnetic structures and makes it a promising building block for antiferromagnetic devices.