Ti has been reported to reach a very high degree of ionization and consequently also high ionized fractions [19]. In our experiments, a maximum ionization fraction of about 60% was reached for a pulse power of 1.8 kW cm− 2 (Fig. 7). In contrast to the case of Ni, there is a continuous increase in the ionization fraction up to the maximum pulse power density. Although the strong magnetic field of the magnetron used in this study may have an effect on both the deposition rate and ionization [29], our results are in good agreement with values reported by Poolcharuansin et al. [14]. In their study, an ionized fraction of Ti of up to 60% using g-QCM was measured. Shorter on-times led to higher ionized fractions of Ti. It is here speculated that longer pulse on-times lead to a successive cooling of the electron temperature as the pulse progresses, due to excitation and ionization of the increasingly larger population of sputtered Ti neutrals. The same trend has also been reported by Poolcharuansin and Bradley [30], and can be understood based on the fact that the first ionization potential of Ti (6.82 eV) is considerably lower compared to Ar (15.76 eV), which decreases the required electron energy needed to provide sufficient ionization to sustain the discharge.