Low-Voltage Control of (Co/Pt) x Perpendicular Magnetic Anisotropy Heterostructure for Flexible Spintronics

ACS Nano. 2018 Jul 24;12(7):7167-7173. doi: 10.1021/acsnano.8b03097. Epub 2018 Jun 8.

Abstract

The trend of mobile Internet requires portable and wearable devices as bio-device interfaces. Electric field control of magnetism is a promising approach to achieve compact, light-weight, and energy-efficient wearable devices. Within a flexible sandwich heterostructure, perpendicular magnetic anisotropy switching was achieved via low-voltage gating control of an ionic gel in mica/Ta/(Pt/Co) x/Pt/ionic gel/Pt, where (Pt/Co) x acted as a functional layer. By conducting in situ VSM, EPR, and MOKE measurements, a 1098 Oe magnetic anisotropy field change was determined at the bending state with tensile strain, corresponding to a magnetic anisotropy energy change of 3.16 × 105 J/m3 and a giant voltage tunability coefficient of 0.79 × 105 J/m3·V. The low voltage and strain dual control of magnetism on mica substrates enables tunable flexible spintronic devices with an increased degree of manipulation.

Keywords: ferromagnetic resonance; flexible magnetoelectric devices; ionic gel gating; perpendicular magnetic anisotropy; voltage control of magnetism.