High-quality single-crystal films of $\mathrm{CoTi}{\mathrm{O}}_3$ were fabricated on a $\mathrm{SrTi}{\mathrm{O}}_3$ substrate using pulsed laser deposition methods, allowing for a detailed investigation of the electronic structure and orbital occupancy via x-ray linear dichroism in both in-plane and out-of-plane configurations. The combination of measurements and semiempirical calculations revealed that the trigonal distortion of $\mathrm{Co}{\mathrm{O}}_6$ octahedra deviating from the cubic crystal field gives rise to an additional trigonal crystal field of ${\mathrm{\Delta }}_{\mathrm{trig}}=45\mathrm{meV}$, with a low-lying $e_g^{\pi }$ orbital of the energetic splitting of the $t_{2g}$ band. Additionally, the x-ray magnetic circular dichroism (XMCD) at the Co $L_{2,3}$ edge captured significant magnetic anisotropy and unquenched orbital angular momentum inherent in the film. An in-plane exchange field of −0.65 meV is required in the multiplet simulation to well reproduce the XMCD spectra obtained with field applied in the in- and out-of-plane directions. These findings provide insights into the potential of $\mathrm{CoTi}{\mathrm{O}}_3$ to align with the Kitaev model when it is presented as a thin film, which is crucial for the further realization of quantum spin liquids via strain engineering.

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• Electronic structure
• Magnetic anisotropy
• Complex materials
• X-ray absorption spectroscopy