Epitaxial HoN thin films: An investigation of the structural, electronic, and magnetic properties

Rare nitrates have been investigated since the 1960s, but there are still many uncertainties regarding their properties and electronic structure due to a lack of clarity in the research. In particular, early bark samples from the 1960s and 1970s have produced varying reports on their properties. Nitrogen vacancies and oxygen contamination have been significant issues in recent decades.

Advancements in film deposition technologies have allowed for better growth of rare nitrates under vacuum conditions with some control over structure and contamination. However, preparation remains challenging due to high defect concentrations caused by factors such as high nitrogen pressure, deposition rates, growth temperatures, and evaporation temperatures. This necessitates the use of beam evaporators. The use of plasma sources can also introduce additional defects.

Furthermore, there is a lack of suitable substrates for the growth of rare nitrates, resulting in poor crystallinity. These challenges highlight the need for further research and development in this area.