Néel temperature tuning in Magnetoelectric B-doped Cr₂O₃ films

Multi-functional thin films of boron (B) doped Cr₂O₃ exhibit voltage-controlled and nonvolatile Néel vector π/2 rotation in the absence of a magnetic field. Isothermal toggling of antiferromagnetic states is demonstrated in prototype device structures at CMOS compatible temperatures between 300 K and 400 K. Néel vector rotation is detected with the help of heavy metal (Pt) Hall-bars in proximity of pulsed laser deposited B:Cr₂O₃ films. Cold neutron depth profiling (cNDP), performed at National Institute of Standards and Technology, reveals thermally activated B-accumulation at the B:Cr2O3/ vacuum interface in thin films deposited on Al2O3 substrates. This work uses cNDP, Spin Hall measurements and Xray Photon Spectroscopy [1-3] to demonstrate a shift in T_N towards higher values of ≈ 477 K, associated with the increase in B-concentration within an interfacial layer of about 50 nm.

[1] A. Mahmood et al., Adv. Physics. Res., 2023, 2300061

[2] A. Erickson, SQA Shah, A. Mahmood, et al., Advanced Functional Materials 2408542, 2024.

[3] A. Mahmood et al., Nat. Comm. 12, 1674 (2021)