Néel Skyrmion Bubbles in La_0.7Sr_0.3Mn_1-RuO₃ Multilayers

Area of Science:

• Materials Science
• Condensed Matter Physics
• Thin Film Technology

Background:

• Epitaxial multilayers offer tunable magnetic properties.
• Engineering magnetic anisotropy and exchange interactions is crucial for novel magnetic phenomena.
• Oxide thin films are promising for advanced electronic applications.

Purpose of the Study:

• Synthesize ferromagnetic La_0.7Sr_0.3Mn_1-RuO₃ epitaxial multilayers.
• Engineer canted magnetic anisotropy and variable exchange interactions.
• Investigate the potential for generating Dzyaloshinskii-Moriya interaction and nontrivial magnetic topology.

Main Methods:

• Epitaxial multilayer synthesis with controlled Ru/Mn content.
• Magnetic Force Microscopy (MFM) under varying perpendicular magnetic fields.
• Lorentz Transmission Electron Microscopy (LTEM) to observe domain structures.
• Micromagnetic modeling to interpret experimental observations.

Main Results:

• Observed magnetic stripe domains with Néel-type domain walls.
• Identified Néel skyrmions smaller than 100 nm in diameter.
• Experimental findings consistent with micromagnetic modeling.

Conclusions:

• The synthesized La_0.7Sr_0.3Mn_1-RuO₃ multilayers exhibit magnetic skyrmions.
• A sizable Dzyaloshinskii-Moriya interaction is present, likely due to inversion symmetry breaking and strain.
• These findings demonstrate the potential for creating nontrivial magnetic topology in oxide thin films.