Nondoped and 5.0 mol% Eu3+-doped vanadate garnets Ca5Mg4(VO4)6, NaCa2Mg2[VO4]3, KCa2Mg2[VO4]3, and NaSr2Mg2[VO4]3 were synthesized by solid-state reactions. The formation of single-phase compound with garnet structure is confirmed by X-ray diffraction. The photoluminescence (PL) and PL excitation (PLE) spectra are investigated together with color coordinates. The luminescence process is discussed on the charge-transfer transitions in [VO4]3− ions and the crystal structure. The PL quantum efficiencies (QE) are measured for nondoped and Eu3+-doped samples. The Eu3+-doped samples have higher QEs than the corresponding nondoped ones although the energy transfer occurs from [VO4]3− to Eu3+. Broad emission band due to [VO4]3− with intense sharp lines due to Eu3+, which gives white color, is observed in Eu3+-doped NaCa2Mg2[VO4]3 and NaSr2Mg2[VO4]3 under excitation with UV light. These materials are suggested to be useful for lighting under the excitation with near-UV LED.

中文翻译：

---

Eu3+ 掺杂钒酸盐石榴石的发光和量子效率

通过固态反应合成了未掺杂和 5.0 mol% Eu3+ 掺杂的钒酸盐石榴石 Ca5Mg4(VO4)6、NaCa2Mg2[VO4]3、KCa2Mg2[VO4]3 和 NaSr2Mg2[VO4]3。X射线衍射证实了石榴石结构的单相化合物的形成。光致发光 (PL) 和 PL 激发 (PLE) 光谱与颜色坐标一起研究。在[VO4]3-离子中的电荷转移跃迁和晶体结构上讨论了发光过程。测量未掺杂和 Eu3+ 掺杂样品的 PL 量子效率 (QE)。尽管能量转移发生在 [VO4]3- 到 Eu3+，Eu3+ 掺杂的样品比相应的非掺杂样品具有更高的 QE。[VO4]3− 产生的宽发射带和 Eu3+ 产生的强烈锐线，产生白色，在紫外光激发下在 Eu3+ 掺杂的 NaCa2Mg2[VO4]3 和 NaSr2Mg2[VO4]3 中观察到。建议这些材料可用于近紫外 LED 激发下的照明。