Abstract
Interfacial magnetism stimulates the discovery of giant magnetoresistance (MR) and spin–orbital coupling across the heterointerfaces, facilitating the intimate correlation between spin transport and complex magnetic structures. Over decades, functional heterointerfaces composed of nitrides have seldom been explored due to the difficulty in synthesizing high-quality nitride films with correct compositions. Here, the fabrication of single-crystalline ferromagnetic Fe3N thin films with precisely controlled thicknesses is reported. As film thickness decreases, the magnetization dramatically deteriorates, and the electronic state changes from metallic to insulating. Strikingly, the high-temperature ferromagnetism is maintained in a Fe3N layer with a thickness down to 2 u.c. (≈8 Å). The MR exhibits a strong in-plane anisotropy; meanwhile, the anomalous Hall resistivity reverses its sign when the Fe3N layer thickness exceeds 5 u.c. Furthermore, a sizable exchange bias is observed at the interfaces between a ferromagnetic Fe3N and an antiferromagnetic CrN. The exchange bias field and saturation moment strongly depend on the controllable bending curvature using the cylinder diameter engineering technique, implying the tunable magnetic states under lattice deformation. This work provides a guideline for exploring functional nitride films and applying their interfacial phenomena for innovative perspectives toward practical applications.
| Original language | English |
|---|---|
| Article number | 2208221 |
| Journal | Advanced Materials |
| Volume | 35 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jan 12 2023 |
Funding
This work was supported by the National Key Basic Research Program of China (Grant Nos. 2020YFA0309100 and 2019YFA0308500), the National Natural Science Foundation of China (Grant Nos. 11974390, 11721404, 11874412, and 12174437), the Beijing Nova Program of Science and Technology (Grant No. Z191100001119112), the Beijing Natural Science Foundation (Grant No. 2202060), the Guangdong‐Hong Kong‐Macao Joint Laboratory for Neutron Scattering Science and Technology, and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB33030200). The PNR experiments on a CrN/FeN bilayer were conducted with multiple purpose reflectometry (MR) at the Chinese Spallation Neutron Source (CSNS) and the PNR experiments on the CrN/FeN superlattices were conducted via a user proposal at Magnetism Reflectometer (BL‐4A) at the Spallation Neutron Source (SNS), a DOE Office of Science user facility operated by Oak Ridge National Laboratory (ORNL). 3 3 This work was supported by the National Key Basic Research Program of China (Grant Nos. 2020YFA0309100 and 2019YFA0308500), the National Natural Science Foundation of China (Grant Nos. 11974390, 11721404, 11874412, and 12174437), the Beijing Nova Program of Science and Technology (Grant No. Z191100001119112), the Beijing Natural Science Foundation (Grant No. 2202060), the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology, and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB33030200). The PNR experiments on a CrN/Fe3N bilayer were conducted with multiple purpose reflectometry (MR) at the Chinese Spallation Neutron Source (CSNS) and the PNR experiments on the CrN/Fe3N superlattices were conducted via a user proposal at Magnetism Reflectometer (BL-4A) at the Spallation Neutron Source (SNS), a DOE Office of Science user facility operated by Oak Ridge National Laboratory (ORNL).
Keywords
- Fe N
- cylinder diameter engineering
- exchange bias
- magnetic anisotropy