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

Abstract

We report our study on the growth of HoN thin films on MgO (100) and ${\mathrm{LaAlO}}_{3}$ (100) substrates. By using molecular beam epitaxy, we thermally evaporate holmium in an atmosphere of molecular nitrogen, forming HoN at slow rates, moderate temperatures and pressures. We are able to carefully and systematically vary the growth conditions, thereby tuning the nitrogen content of our samples. We explore the differences in the growth window by looking at the crystalline structure and composition of the films deposited on the different substrates. We find that HoN has an epitaxial, well-ordered growth on ${\mathrm{LaAlO}}_{3}$, in contrast to the three-dimensional growth that occurs on MgO. Using a combination of in situ electron diffraction and x-ray spectroscopies, as well as ex situ x-ray diffraction and SQUID magnetometry, we investigate the structural, electronic, and magnetic properties of the epitaxial HoN films.