## 3 Results and Discussion
In a previous study, the spectra of BaZrO\({}_{3}\) doped with Eu\({}^{3+}\) powders consisted of a series of resolved emission peaks located at 576 nm, 597 nm, 616 nm, 623 nm, 651 nm, 673 nm, 696 nm, and 704 nm, which are assignable to the \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{1}\) (\(J\) = 0, 1, 2, 3, 4) transitions of Eu\({}^{3+}\) ions, namely, \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{0}\) (576 nm), \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{1}\) (597 nm), \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{2}\) (616 nm, 623 nm), \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{3}\) (651 nm), and \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{4}\) (673 nm, 696 nm, and 704 nm) [16]. [PERSON] and [PERSON]'s research also showed that the emission intensities of \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{0}\) (576 nm), \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{1}\) (597 nm), and \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{2}\) (616, 623 nm) had almost the same values, even if the Eu concentration in the BaZr\({}_{1-x}\)Eu\({}_{x}\)O\({}_{3}\) phosphor powders was different [26]. These previous results [6; 16], and the results this study, suggest that the transitions of Eu\({}^{3+}\) ions between different energy bands are affected by the host materials of the prepared phosphors. As the synthesizing temperature was changed from 900 \({}^{\circ}\)C to 1100 \({}^{\circ}\)C, the intensities of the two emission peaks of the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors was enhanced by increasing the Eu\({}^{3+}\) doping concentration and reached a maximum value at \(x\) = 0.08. In contrast, the intensities of the two emission peaks of the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors decreased when the Eu\({}^{3+}\) doping ratio was more than 0.08. This proves that the concentration-quenching effect of Eu\({}^{3+}\) doping happened in the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoOphosphors. When 1200 \({}^{\circ}\)C was used as the sintering temperature, the intensities of the two emission peaks of the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors increased as the concentration of Eu\({}^{3+}\) ions rose. The results in Figure 3 also show that when the temperature changed from 1100 \({}^{\circ}\)C to 1200 \({}^{\circ}\)C, the emission peak varied significantly. For the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors, when the synthesizing temperature was changed from 1100 \({}^{\circ}\)C to 1300 \({}^{\circ}\)C, the emission peak with the maximum intensity shifted from \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{1}\) (597 nm) to \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{2}\) (616 nm). Nevertheless, the strong band at 576 nm corresponding to the \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{0}\) transition was not observed in the emission spectra. The maximum emission intensities (PL\({}_{\text{max}}\) values) of the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors in the transitions of the \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{1}\) (597 nm) and \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{2}\) (616 nm) peaks are presented in Figure 4 as a function of the synthesizing temperature and Eu\({}^{3+}\) ion concentration. Those results suggest again that the PL characteristics of the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors were strongly affected by the synthesizing temperature and the concentration of Eu\({}^{3+}\) ions. As the \(x\) value of the Sr\({}_{2-x}\)Eu\({}_{x}\)ZnMoO\({}_{6}\) phosphors was smaller than 0.10, the emission intensities of the \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{1}\) (597 nm) and \({}^{5}\)D\({}_{0}\)-\({}^{7}\)F\({}_{2}\) (616 nm) peaks first increased, reached a maximum, and then decreased as the synthesizing temperature increased.