Ferrites in thin film form are usually obtained by pulsed laser deposition (PLD). This method can induce the presence of secondary phases, a problem which requires an annealing process. The study aimed at finding a PLD based method through which, in further studies, ferrites with a controllable phase composition can be obtained. Therefore, we obtained ferrite thin films in oxygen atmosphere and in high vacuum. Raman spectroscopy measurements for the samples obtained in high vacuum revealed the formation of magnetite. Instead of annealing, we irradiated these samples with an excimer laser (λ = 308 nm), at various frequencies, for certain amount of pulses. The Raman spectra revealed the formation of the nickel ferrite phase, as well as the presence of residual magnetite phase.