Observation of anomalous Hall effect in a new noncoplanar antiferromagnetic structure

Antiferromagnets (AFMs) have garnered significant interest as promising candidates for next-generation spintronic devices. However, the readout of AFMs is a core issue due to their negligible net magnetization. Nowadays researchers find that the anomalous Hall effect (AHE) in AFMs is critical for realizing the tunneling magnetoresistance, which is efficient for AFM readout. The exploring of new AFM structures that can host AHE could further move the research on mechanism in unconventional AFMs. In this work, we report an AHE in a new noncoplanar AFM structure with the magnetic space group of RΙ3¯c. The RΙ3¯c phase is successfully stabilized in the Mn2.6Cr0.4GaN epitaxial film. Through the analysis of the relationship between anomalous Hall resistivity ρyxA and saturation moment MS, the AHE is confirmed to arise from the RΙ3¯c AFM structure. The corresponding anomalous Hall conductivity exceeding 50 Ω−1 cm−1 is observed, which is comparable with other noncollinear AFMs. The findings present a novel candidate for AFM spintronic materials and provide a new reference for understanding the essence of AHE in AFM structures.