Voltage control of magnetization via strain in piezoelectric/magnetostrictive systems is a promising mechanism to implement energy-efficient straintronic memory devices. Here, we demonstrate giant voltage manipulation of MgO magnetic tunnel junctions (MTJ) on a Pb(Mg1/3Nb2/3)0.7Ti0.3O3 piezoelectric substrate with (001) orientation. It is found that the magnetic easy axis, switching field, and the tunnel magnetoresistance (TMR) of the MTJ can be efficiently controlled by strain from the underlying piezoelectric layer upon the application of a gate voltage. Repeatable voltage controlled MTJ toggling between high/low-resistance states is demonstrated. More importantly, instead of relying on the intrinsic anisotropy of the piezoelectric substrate to generate the required strain, we utilize anisotropic strain produced using a local gating scheme, which is scalable and amenable to practical memory applications. Additionally, the adoption of crystalline MgO-based MTJ on piezoelectric layer lends itself to high TMR in the strain-mediated MRAM devices.
|Original language||English (US)|
|Journal||Applied Physics Letters|
|State||Published - Aug 29 2016|
Bibliographical noteFunding Information:
This work was partially supported by the Center for Spintronic Materials, Interfaces and Novel Architectures (C-SPIN), one of six SRC STARnet Centers. N. D'Souza and J. Atulasimha were partially supported by NSF CAREER Grant No. CCF-1253370. S. Bandyopadhyay was supported by the NSF Grant No. ECCS 1124714.
© 2016 Author(s).