Mahmood Ather, Echtenkamp Will, Street Mike, Wang Jun-Lei, Cao Shi, Komesu Takashi, Dowben Peter A, Buragohain Pratyush, Lu Haidong, Gruverman Alexei, Parthasarathy Arun, Rakheja Shaloo, Binek Christian
Department of Physics & Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE, USA.
Department of Electrical Engineering, New York University, Brooklyn, NY, USA.
Nat Commun. 2021 Mar 15;12(1):1674. doi: 10.1038/s41467-021-21872-3.
Multi-functional thin films of boron (B) doped CrO 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:CrO 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 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:CrO a promising multifunctional single-phase material for energy efficient nonvolatile CMOS compatible memory applications.
硼（B）掺杂的CrO多功能薄膜在无外加磁场H的情况下表现出电压控制的非易失性奈尔矢量重取向。在300至400 K的CMOS兼容温度下，在原型器件结构中演示了反铁磁状态的切换。与奈尔矢量取向相关的边界磁化用作状态变量，通过与B:CrO薄膜相邻的Pt霍尔条中的磁阻检测来读取。霍尔电压在零和非零值之间的切换意味着奈尔矢量旋转90度。综合磁测量、自旋分辨逆光电子发射、电输运和扫描探针显微镜测量揭示了与B相关的温度和电阻率增强、自旋倾斜、各向异性降低、动态极化滞后以及边界磁化的栅极电压依赖性取向。这些综合效应使得在高温下能够实现H = 0、电压控制的非易失性奈尔矢量旋转。理论建模估计开关速度约为100 ps，这使得B:CrO成为用于节能非易失性CMOS兼容存储器应用的有前途的多功能单相材料。
