Crystallization and photoluminescence properties of α-RE2(WO4)3 (RE: Gd, Eu) in rare-earth tungsten borate glasses

Glasses with the compositions of 22.5RE2O3–47.5WO3–30B2O3 (mol%) (RE: Gd, Eu) were prepared by a conventional melt quenching method, and α-Gd2(WO4)3 and α-Eu2(WO4)3 crystals were synthesized through their crystallization. The two types of WO4 tetrahedra present in α-RE2(WO4)3 provide the Raman bands at 931–934 cm−1 for WIIO4 tetrahrdra with much distortions and at 946–950 cm−1 for WIO4 tetrahedra with a near regular symmetry. The crystallized samples containing α-Eu2(WO4)3 exhibit strong red emissions under the excitation at 396 and 467 nm, although the base glass has no photoluminescence emission. α-Gd2(WO4)3 and α-Eu2(WO4)3 crystals were patterned on the glass surface by irradiations of a continuous wave Yb:YVO4 fiber laser (wavelength: 1080 nm).

► Glasses of 22.5RE2O3–47.5WO3–30B2O3 (mol%) (RE: Gd, Eu) are prepared by a melt quenching method.
► α-Gd2(WO4)3 and α-Eu2(WO4)3 crystals are synthesized through the crystallization of glasses.
► Raman spectra of crystallized glasses are discussed.
► Crystallized samples with α-Eu2(WO4)3 exhibit strong red emissions.
► α-RE2(WO4)3 crystals are patterned on the glass surface by laser irradiations.