Magnetic Structure-Dependent Spin Texture Lattice in Hexagonal MnFeCoGe Magnets

Area of Science:

• Materials Science
• Condensed Matter Physics
• Magnetism

Background:

• Topological spin textures are crucial for advanced magnetic information storage and spintronics.
• These textures offer high storage density and low energy consumption.
• Understanding their formation and manipulation is key to developing next-generation devices.

Purpose of the Study:

• To investigate the transformation of magnetic configurations in MnFe$_{1-x}$Co$_x$Ge.
• To explore the creation of stable, high-density topological spin textures.
• To establish a strategy for designing novel spintronic materials.

Main Methods:

• Synthesis and characterization of MnFe$_{1-x}$Co$_x$Ge alloys with varying Co content.
• Neutron diffraction and Lorentz transmission electron microscopy (L-TEM) for magnetic structure analysis.
• Out-of-plane magnetic field stimulation and field-cooling to induce bubble lattices.
• Micromagnetic simulations to confirm magnetic interactions.

Main Results:

• Observed transformation from labyrinth to stripe magnetic domains with increasing Co content.
• Identified a transition from noncollinear to uniaxial ferromagnetic structures.
• Successfully established a hexagonal lattice of robust type-II magnetic bubbles for $x=0.8$.
• Demonstrated that bubble dimensions can be tuned by sample thickness.

Conclusions:

• Magnetic structure manipulation in MnFe$_{1-x}$Co$_x$Ge stabilizes complex topological spin textures.
• Enhanced uniaxial ferromagnetic and dipole-dipole interactions are key to this stabilization.
• This provides an efficient strategy for designing topological spin textures for spintronic applications.