  By means of photoemission and x-ray absorption spectroscopy, we have studied
the electronic structure of (Ni,Zn,Fe,Ti)$_{3}$O$_{4}$ thin films, which
exhibits a cluster glass behavior with a spin-freezing temperature $T_f$ of
$\sim 230$ K and photo-induced magnetization (PIM) below $T_f$. The Ni and Zn
ions were found to be in the divalent states. Most of the Fe and Ti ions in the
thin films were trivalent (Fe$^{3+}$) and tetravalent (Ti$^{4+}$),
respectively. While Ti doping did not affect the valence states of the Ni and
Zn ions, a small amount of Fe$^{2+}$ ions increased with Ti concentration,
consistent with the proposed charge-transfer mechanism of PIM.
