Oriented 3D Magnetic Biskyrmions in MnNiGa Bulk Crystals

Area of Science:

• Condensed Matter Physics
• Materials Science
• Magnetism

Background:

• Biskyrmions are topologically stable spin textures observed via Lorentz transmission electron microscopy (LTEM).
• Their three-dimensional structure and ordering in bulk materials remain unclear from LTEM imaging alone.

Purpose of the Study:

• Investigate the biskyrmion form factor in MnNiGa samples.
• Determine the ordering and structural properties of biskyrmions in bulk.
• Explore the influence of magnetocrystalline anisotropy on biskyrmion arrangement.

Main Methods:

• Small-angle neutron scattering (SANS) was employed to probe biskyrmion structure.
• Analysis was performed on both single- and polycrystalline-MnNiGa samples.
• LTEM was used for initial observation and comparison.

Main Results:

• Biskyrmions were found to be disordered, lacking long-range order even in single crystals.
• Despite disorder, biskyrmions exhibit alignment along specific in-plane directions.
• This alignment is dictated by the magnetocrystalline anisotropy of the material.

Conclusions:

• Biskyrmions are not necessarily long-range ordered 3D structures in bulk.
• Magnetocrystalline anisotropy plays a crucial role in orienting disordered biskyrmions.
• The anisotropic nature of biskyrmions presents opportunities for novel information encoding applications.