Spin-dependent transport properties of Fe3O4/MoS2/Fe3O4 junctions

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Magnetite (Fe3O4) is a half-metal with a high Curie temperature, ideal for magnetic tunnel junctions (MTJs).
• Previous Fe3O4/MgO/Fe3O4 MTJ structures faced challenges in maintaining Fe3O4's half-metallic properties at interfaces.
• Two-dimensional (2D) materials are explored as potential solutions for interface stability.

Purpose of the Study:

• To investigate molybdenum disulfide (MoS2) as a barrier layer in Fe3O4-based MTJs.
• To theoretically and experimentally assess the interface properties between Fe3O4 and MoS2.
• To determine the viability of MoS2 for fabricating functional Fe3O4/MoS2/Fe3O4 MTJs.

Main Methods:

• First-principle calculations to analyze spin polarization at the Fe3O4/MoS2 interface.
• Fabrication of Fe3O4/MoS2/Fe3O4 magnetic tunnel junction structures.
• Experimental measurement of tunneling magnetoresistance (TMR) signals.

Main Results:

• First-principle calculations confirm that Fe3O4 maintains nearly fully spin-polarized electron bands at the MoS2 interface.
• Fe3O4/MoS2/Fe3O4 MTJs were successfully fabricated, exhibiting a clear TMR signal below 200 K.
• Calculations suggest that junctions with monolayer or bilayer MoS2 are metallic.

Conclusions:

• Molybdenum disulfide (MoS2) is a suitable barrier material for Fe3O4-based MTJs.
• The use of MoS2 preserves the crucial half-metallic nature of Fe3O4 at the interface.
• This research opens avenues for developing advanced spintronic devices using Fe3O4/MoS2 heterostructures.