X-ray absorption and x-ray magnetic circular dichroism in bulk and thin films of ferrimagnetic GdTiO3

Perovskite rare-earth titanates are prototypical Mott insulators in which ${\mathrm{Ti}}^{3+}$ ions with $3{d}^{1}$ electronic configuration exhibit ferromagnetic or antiferromagnetic spin order, depending on the size. This peculiar magnetic behavior has, however, been barely studied element-specific probes, either bulk thin films. The recent finding of fingerprints ferromagnetism two-dimensional electron gases at oxide interfaces involving has produced a surge interest these complex materials. Harnessing interfacial states heterostructures calls for better understanding their insufficiently explored and especially film form. In this paper, we combine high-resolution transmission microscopy x-ray absorption spectroscopy circular dichroism (XMCD) to determine structural, electronic, structure $\mathrm{GdTi}{\mathrm{O}}_{3}$ both cases, find that sample surface is strongly overoxidized but few nm below, Ti mostly 3+ shows large XMCD. We provide evidence ferrimagnetic nature antialigned Gd sublattices show that, just as $\mathrm{LaTi}{\mathrm{O}}_{3}$ $\mathrm{YTi}{\mathrm{O}}_{3}$, carries no orbital moment.