Voltage controlled Néel vector rotation in zero magnetic field.

Multi-functional thin films of boron (B) doped Cr2O3 exhibit voltage-controlled and nonvolatile Neel vector reorientation in the absence of an applied magnetic field, H. Toggling of antiferromagnetic states is demonstrated in prototype device structures at CMOS compatible temperatures between 300 and 400 K. The boundary magnetization associated with the Neel vector orientation serves as state variable which is read via magnetoresistive detection in a Pt Hall bar adjacent to the B:Cr2O3 film. Switching of the Hall voltage between zero and non-zero values implies Neel vector rotation by 90 degrees. Combined magnetometry, spin resolved inverse photoemission, electric transport and scanning probe microscopy measurements reveal B-dependent TN and resistivity enhancement, spin-canting, anisotropy reduction, dynamic polarization hysteresis and gate voltage dependent orientation of boundary magnetization. The combined effect enables H = 0, voltage controlled, nonvolatile Neel vector rotation at high-temperature. Theoretical modeling estimates switching speeds of about 100 ps making B:Cr2O3 a promising multifunctional single-phase material for energy efficient nonvolatile CMOS compatible memory applications. Voltage control of magnetization is critical for the development of antiferromagnetic spintronics. Here, using magnetic force microscopy and Hall measurements, Mahmood et al. demonstrate controlled rotation of the Neel vector in a heterostructure composed of Pt and antiferromagnetic B:Cr2O3.