Thermal Contribution in the Electrical Switching Experiments with Heavy Metal / Antiferromagnet Structures

Abstract

We examine the thermal origin of the detected "saw-tooth" shaped Hall resistance (Rxy) signals in the spin-orbit torque switching experiment for antiferromagnetic MnN. Compared with the results of the heavy metal / antiferromagnet bilayers (MnN/Ta), the qualitatively same "saw-tooth" shaped signals also appear in the samples with the heavy metal layer alone (either Ta or Pt) without MnN layer. In addition, The Rxy signal changes oppositely in the devices with Ta and Pt, due to the opposite temperature coefficient of resistivity (TCR) of the two materials. All those results are consistent with the "localized Joule heating" mechanism in devices with Hall crosses geometry. Moreover, by utilizing a structure with separated writing current paths and Hall cross area, the quadratic relationship between delta-Rxy and the writing current's amplitude is observed, which provides quantitative evidence of the thermal contribution. These results reveal the dominant thermal artifact in the widely used Hall crosses geometry for Neel vector probing, and also provide a strategy to semi-quantitatively evaluate the thermal effect, which can shed light on a more conclusive experiment design.

All the experiments presented in this paper were carried out and completed before Sep. 2018

References in corpus (9)

• Robust isothermal electric switching of interface magnetization: A route to voltage-controlled spintronics
• Electric-field-induced spin-flop in BiFeO3 single crystals at room-temperature
• Writing and Reading antiferromagnetic Mn${}_2$Au: Néel spin-orbit torques and large anisotropic magnetoresistance
• Purely Antiferromagnetic Magnetoelectric Random Access Memory
• Negative spin Hall magnetoresistance of Pt on the bulk easy-plane antiferromagnet NiO
• Imaging of current induced Néel vector switching in antiferromagnetic Mn${}_2$Au
• Concurrent magneto-optical imaging and magneto-transport readout of electrical switching of insulating antiferromagnetic thin films
• Direct Imaging of Electrical Switching of Antiferromagnetic Néel Order in $\alpha$-Fe${}_2$O${}_3$ Epitaxial Films
• Systematic study of nonmagnetic resistance changes due to electrical pulsing in single metal layers and metal/antiferromagnet bilayers

Cited by in corpus (1)

• Vector spin Seebeck effect and spin swapping effect in antiferromagnetic insulators with non-collinear spin structure