Strain-Controlled Giant Magnetoresistance in Spin Valves Grown on Shape Memory Alloys

Abstract

We report a strain-mediated giant magnetoresistance (GMR) in spin valves (SPVs) grown on shape memory alloys (SMAs). The SPVs with a stacking structure of Al2O3/Co90Fe10/Cu/Co90Fe10/IrMn/Pt were deposited on NiTi and NiTiNb SMA substrates with and without predeformation. The GMR of the SPVs on the precompressed NiTi substrates changes after annealing, whereas the one on SMAs without predeformation remains unchanged under the same annealing treatment. Especially, the GMR of the SPVs on the NiTiNb substrates can be reversibly modulated under a thermocycling treatment on account of the shape memory effect caused by the phase transitions of NiTiNb. The study demonstrates a new strain-mediated approach to reversibly control GMR through phase transitions, which provides a potential way to design strain-sensitive spintronic devices.

Diverse electronic and magnetic properties of CrS2 enabling strain-controlled 2D lateral heterostructure spintronic devices

“…The working mechanism is to transfer a piezoelectric strain generated from the substrate to the FM layer to modify its magnetic easy-axis via the inverse magnetostriction effect. Such a strain-controlled spin valve has low energy consumption 18,19 . But these devices have complex structures (e.g., 11 layers of different materials) 16 .…”