Boron (B) alloying transforms the magnetoelectric antiferromagnet Cr2O3into a multifunctional single‐phase material which enables electric field driven π/2 rotation of the Néel vector. Nonvolatile, voltage‐controlled Néel vector rotation is a much‐desired material property in the context of antiferromagnetic spintronics enabling ultralow power, ultrafast, nonvolatile memory, and logic device applications. Néel vector rotation is detected with the help of heavy metal (Pt) Hall‐bars in proximity of pulsed laser deposited B:Cr2O3films. To facilitate operation of B:Cr2O3‐based devices in CMOS (complementary metal‐oxide semiconductor) environments, the Néel temperature,
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Chromia (Cr2O3) is a magnetoelectric oxide that permits voltage‐control of the antiferromagnetic (AFM) order, but it suffers technological constraints due to its low Néel Temperature (
- Award ID(s):
- 2044049
- PAR ID:
- 10529798
- Publisher / Repository:
- Advanced Functional Materials published by Wiley-VCH GmbH
- Date Published:
- Journal Name:
- Advanced Functional Materials
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)Abstract Multi-functional thin films of boron (B) doped Cr 2 O 3 exhibit voltage-controlled and nonvolatile Néel 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 Néel vector orientation serves as state variable which is read via magnetoresistive detection in a Pt Hall bar adjacent to the B:Cr 2 O 3 film. Switching of the Hall voltage between zero and non-zero values implies Néel vector rotation by 90 degrees. Combined magnetometry, spin resolved inverse photoemission, electric transport and scanning probe microscopy measurements reveal B-dependent T N 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 Néel vector rotation at high-temperature. Theoretical modeling estimates switching speeds of about 100 ps making B:Cr 2 O 3 a promising multifunctional single-phase material for energy efficient nonvolatile CMOS compatible memory applications.more » « less
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