Removable capping layer for air-sensitive GdN.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Rare earth nitrides exhibit complex coupled magnetic, electronic, and superconducting properties.
• Predicted topological states in these materials are of significant scientific interest.
• Air-sensitivity of rare earth nitrides hinders comprehensive property investigations.

Purpose of the Study:

• To develop a passivation method for air-sensitive gadolinium nitride (GdN) thin films.
• To enable ex-situ magnetic and structural characterization of GdN.
• To demonstrate the successful removal of the passivation layer and recovery of the GdN surface.

Main Methods:

• Epitaxial growth of a 100 nm samarium (Sm) passivation layer on 100 nm GdN thin films.
• Characterization using reflection high-energy electron diffraction (RHEED), atomic force microscopy (AFM), and energy dispersive X-ray spectroscopy (EDS).
• Investigation of Sm layer thermal desorption under vacuum and its removal via argon ion sputtering and thermal desorption at 400 °C.

Main Results:

• The samarium layer effectively passivates GdN thin films against air exposure.
• Ex-situ magnetic and structural analyses of GdN were successfully performed.
• The samarium capping layer could be removed, restoring the GdN surface after air exposure.

Conclusions:

• Epitaxial samarium layers offer a viable passivation strategy for rare earth nitrides like GdN.
• This technique facilitates in-depth studies of these technologically relevant materials.
• The developed method opens avenues for exploring the unique properties of rare earth nitrides.