Strain Controlled Ultra-Low-Energy Magnetic Tunneling Junction

Authors

Hasnain AhmadFollow
Supriyo Bandyopadhyay, Virginia Commonwealth University
Jayasimha Atulasimha, Virginia Commonwealth University

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Abstract

We are experimenting on designing a voltage-controlled ultra-low-energy Magnetic Tunneling Junction (MTJ) device using a soft single domain magnetostrictive layer (i.e. Galfenol: Fe_1-xGa_x , x = 20 At%) coupled to a piezoelectric layer (i.e. PMN-PT). Special metal pads have been designed using photolithography to generate stress in the PMN-PT layer by applying electric field. The patterns of different shape anisotropic nano-magnets are designed using e-beam lithography and we have successfully fabricate FeGa nanomagnets with only 12 to 13 nanometer thickness by sputter deposition. These nanomagnets have been characterized by magnetic force microscopy for observing their switching capabilities. Several nano-magnets have shown magnetization reversal after applying stress. Magnetic domain pinning, shape irregularity, irregular edges in the pattern, strain gradients across the FeGa etc. are several factors that we are still trying to optimize. The next step will be to deposit a tunneling oxide layer and hard ferromagnetic layer to complete the MTJ. These simple strain controlled MTJs can act as non-volatile NAND and NOR gate depending on the shape anisotropy barrier of the soft ferromagnetic layer (FeGa) and are extremely energy-efficient.

Publication Date

2015

Keywords

Magnetostriction, Multiferroic, Magnetic Tunneling Junction, Galfenol

Disciplines

Electronic Devices and Semiconductor Manufacturing | Nanotechnology Fabrication

Faculty Advisor/Mentor

Dr. Supriyo Bandyopadhyay, Dr. Jayasimha Atulasimha

Is Part Of

VCU Graduate Research Posters