Junhu Zhang(张军虎), Fengzi Zhou, Dandan Wang, Jingxue Wang, Lin Lin(林林), Jiasheng Li, Wanwan Shi, Yongliang Yong, Weiwei Ju, Shuhan Zheng, Bing Yu, Wenjing Zhai, Rui Chen, Guanzhong Zhou, Yongqiang Li, Zhibo Yan, and Junming Liu(刘俊明)
Magnetoelectric coupling and its microscopic origin in the honeycomb antiferromagnet BaNi2(PO4)2
Physical Review B 114, 134429 (2026)
The magnetoelectric (ME) effect, the induction of electric polarization (P) by an applied magnetic field or magnetization (M) by an electric field, provides a pathway for low-power-consumption data memory devices. In this work, we present a systematic experimental investigation of the magnetism, heat capacity, and anisotropic ME effect in BaNi2(PO4)2 single crystals. Our results reveal long-range antiferromagnetic (AFM) ordering below the Néel temperature TN = 24K, where the Ni2+ spins are AFM aligned along the x // [1-10] axis. Detailed ME measurements reveal that BaNi2(PO4)2 exhibits dominant out-of-plane electric polarization and significant in-plane electric polarization along the y // [110] direction. The largest magnetically induced electric polarization of 128 μC/m2 along the z // [001] axis is observed at T = 2 K under the magnetic field of μ0H = 9 T applied along the x direction, with a ME coefficient of α ∼ 16.8 ps/m. The angular-dependent measurement demonstrates that the induced in-plane electric polarization Py changes its direction by −2θ around the z axis upon rotating the magnetic field H by an angle θ. Based on the crystal and magnetic symmetry of the honeycomb layer, the microscopic origin of in-plane electric polarization Px and Py under H // z and Py under H // x and H // y can be attributed to the inverse Dzyaloshinskii-Moriya mechanism and the spin-dependent p-d hybridization mechanism, respectively. Thus, in this work, we provide insights for understanding the microscopic origin of the ME coupling in linear ME materials.
URL: https://doi.org/10.1103/zzyb-dqvj