Shaped single crystal growth and scintillating application of Yb:(Gd,Lu)3(Ga,Al)5O12 solid solutions

Abstract Shaped single crystals of (Yb 0.05 Lu x Gd 0.95− x )Ga 5 O 12 (0.0⩽ x ⩽0.9) and Yb 0.15 Gd 0.15 Lu 2.7 (Al x Ga 1− x )O 12 (0.0⩽ x ⩽1.0) were grown by the modified micro-pulling-down method. Continuous solid solutions with garnet structure and a linear compositional dependency of crystal lattice parameter in the system Yb:(Gd,Lu) 3 (Ga,Al) 5 O 12 are formed. Measured optical absorption spectra of the samples show 4f–4f transitions related to Gd 3+ ion at 275 and 310 nm, and also an onset of charge transfer transitions from oxygen ligands to Gd 3+ or Yb 3+ cations below 240 nm. A complete absence of Yb 3+ charge transfer luminescence under X-ray excitation in any of the investigated samples was explained by the overlapping of charge transfer absorption of Yb 3+ by that of Gd 3+ ions. For specific composition of Lu 1.5 Gd 1.5 Ga 5 O 12 an intense defect––host lattice-related emission, which achieve of about 40% integrated intensity compared with Bi 4 Ge 3 O 12 , was found.