Analysis of x-ray linear dichroism spectra for NiO thin films grown on vicinal Ag(001)

Abstract

Antiferromagnetic (AFM) NiO thin films are grown epitaxially on vicinal Ag(118) substrate and investigated by x-ray linear dichroism (XLD). We find that the NiO AFM spins exhibit an in-plane spin-reorientation transition from parallel to perpendicular to the step edge direction with increasing the NiO film thickness. In addition to the conventional ${L}_{2}$ absorption edge, XLD effect at the $\text{Ni}\text{ }{L}_{3}$ absorption edge is also measured and analyzed. The results identify a small energy shift of the ${L}_{3}$ peak. Temperature-dependent measurement confirms that the observed XLD effect in this system at the normal incidence of the x rays originates entirely from the NiO magnetic ordering.