It has been known that magnetic properties of a ferromagnet grown on piezoelectric substrates can be altered by the electric field-induced strain. We consider spin-valve CoFe/Cu/CoFe/IrMn grown on (011)-cut piezoelectric Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) substrate and investigate the effect of the electric field on the giant magnetoresistance (GMR) of the spin valve. We found that the electric field induced strain on PMN-PT substrate enhances the coercivity of the magnetic layers. The transport measurement shows that the GMR ratio of the spin valve could be altered as much as 50% for an electric field of -8 kV/cm. The change of GMR is attributed to the reduced maximum degree of the antiparallel alignment between the magnetization directions of the free and pinned layers. The present studies establish a prototype electrically tunable magnetic memory device such that the electric field can reversibly tune spin valve magnetoresistance without deteriorating electric and magnetic properties.
- Converse piezoelectric effect
- giant magnetoresistance
- superconducting quantum interference device
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering