Stabilizing perpendicular magnetic anisotropy with strong exchange bias in PtMn/Co by magneto-ionics

Abstract

Electric field control of magnetic properties offers a broad and promising toolbox for enabling ultra-low power electronics. A key challenge with high technological relevance is to master the interplay between the magnetic anisotropy of a ferromagnet and the exchange coupling to an adjacent antiferromagnet. Here, we demonstrate that magneto-ionic gating can be used to achieve a very stable out-of-plane (OOP) oriented magnetization with strong exchange bias in samples with as-deposited preferred in-plane (IP) magnetization. We show that the perpendicular interfacial anisotropy can be increased by more than a factor 2 in the stack Ta/Pt/PtMn/Co/HfO2 by applying -2.5 V gate voltage over 3 nm HfO2, causing a reorientation of the magnetization from IP to OOP with a strong OOP exchange bias of more than 50 mT. Comparing two thicknesses of PtMn, we identify a notable trade-off: while thicker PtMn yields a significantly larger exchange bias, it also results in a slower response to ionic liquid gating within the accessible gate voltage window. These results pave the way for post-deposition electrical tailoring of magnetic anisotropy and exchange bias in samples requiring significant exchange bias.

main manuscript and supplementary material

References in corpus (5)

• Magneto-ionic Control of Interfacial Magnetism
• Recent progress in voltage control of magnetism: Materials, mechanisms, and performance
• Nitrogen-Based Magneto-Ionic Manipulation of Exchange Bias in CoFe/MnN Heterostructures
• Multiple magneto-ionic regimes in Ta/Co${}_{20}$Fe${}_{60}$B${}_{20}$/HfO${}_2$
• Tuning the dynamics of chiral domain walls of ferrimagnetic films with the magneto-ionic effect

Cited by in corpus (4)

• Surface Oxidation of SnTe Analyzed by Self-Consistent Fitting of all Emission Peaks in its X-ray Photoelectron Spectrum
• Control of magnetic transition, metal-semiconductor transition, and magnetic anisotropy in noncentrosymmetric monolayer Cr${}_2$Ge${}_2$Se${}_3$Te${}_3$
• Depth Profiling of Oxygen Migration in Ta/HfO2 Stacks During Ionic Liquid Gating
• Initialization-Free Multistate Memristor: Synergy of Spin-Orbit Torque and Magnetic Fields