Modulating Multiferroic Control of Magnetocrystalline Anisotropy Using 5d Transition Metal Capping Layers
Andy Paul Chen1,2, Yuan Ping Feng1,3
1NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore, Singapore 117456, Singapore.
ACS Applied Materials & Interfaces
|May 12, 2020
Summary
Electric-field control of magnetocrystalline anisotropy energy (MAE) in STT-MRAM devices is achievable by switching BaTiO3 polarization. The MAE tuning effect depends heavily on the 5d transition metal capping layer, with complex behaviors explained by interface hybridization and band filling.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Magnetocrystalline anisotropy energy (MAE) is crucial for STT-MRAM performance, influencing storage robustness and switching energy.
- Electric-field control of MAE offers a pathway to optimize tunnel junction components in magnetic memory devices.
Purpose of the Study:
- To investigate the electric-field control of MAE in BaTiO3/CoFe heterostructures with various 5d transition metal capping layers.
- To understand the influence of capping layer composition on MAE and electric-field tuning efficiency.
Main Methods:
- Calculated MAE using the frozen potential method for CoFe layers.
- Studied heterostructures comprising BaTiO3, CoFe, and 5d transition metals (Hf, Ta, W, Re, Os, Ir, Pt, Au).
- Employed a second-order perturbation theoretical framework to explain observed phenomena.
Main Results:
- Demonstrated electric-field tuning of MAE is possible by switching BaTiO3 ferroelectric polarization.
- Found that MAE and tuning effects are strongly dependent on the specific 5d transition metal element used in the capping layer.
- Observed complex trends in MAE and polarization effects across the 5d series, linked to interface hybridization and band filling.
Conclusions:
- Electric-field control of MAE in STT-MRAM is feasible, offering tunable magnetic properties.
- The choice of 5d transition metal capping layer critically impacts MAE and its electric-field modulation.
- Theoretical framework successfully explains the intricate relationship between capping layer properties and MAE behavior.
Keywords:
STT-MRAMVCMAbarium titanatedensity of statesferroelectric polarizationfirst-principles calculationmagnetic anisotropymagnetic thin filmMore Related Videos
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