Crystal growth, physical and optical properties of TlSr2Cl5 and TlSr2Br5

Small diameter (Ø 16 mm) TlSr2Cl5 and TlSr2Br5 crystals were grown by the Vertical Bridgman method. X-ray diffraction measurements show that both have the monoclinic crystal structure with space group P21/c. TlSr2Cl5 and TlSr2Br5 have a density of 4.14 g/cm3 and 5.03 g/cm3, respectively. The effective Z of TlSr2Cl5 and TlSr2Br5 is 63.7 and 58.6, respectively. Radioluminescence spectra of TlSr2Cl5 and TlSr2Br5 feature a broad emission band peaking at 440 and 445 nm, respectively. The light yield of TlSr2Cl5 and TlSr2Br5 was estimated to be 17,000 and 45,000 ph/MeV, respectively.