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Bi-doped Lu3Al5O12 (LuAG) single crystalline films (SCFs) of thickness within 8–31 µm were grown by the liquid-phase epitaxy method onto Y3Al5O12 (YAG) single crystal substrates using a melt solution based on a Bi2O3 flux. Their characteristics were compared with YAG : Bi SCFs grown at the same conditions. The concentration of Bi3+ ions in LuAG : Bi and YAG : Bi SCFs was varied by changing the growth temperature in the ranges 0.05–0.18 at% and 0.13–0.57 at%, respectively. The absorption, luminescence and scintillation properties of these SCFs noticeably depend on the Bi3+ concentration. Luminescence spectra of both LuAG : Bi and YAG : Bi SCF consist of two broad emission bands in the UV and visible (VIS) spectral ranges peaking at 4.155–4.085 eV and 2.45–2.66 eV, respectively. Both the UV and VIS luminescence show complex non-exponential decays. Under 241Am α-particle excitation the photoelectron yield of the best performing LuAG : Bi (0.18 at%) and YAG : Bi (0.13 at%) SCFs is about 15% and 21%, respectively, of that of the reference YAP : Ce single crystal.

One of the purposes of this work is to provide a crystallographic review of group 1 and thallium rare-earth ternary sulfides M(+)Ln(3+)S2. We have therefore determined crystal structures of KLaS2, KPrS2, KEuS2, KGdS2, KLuS2, KYS2, RbYS2, which belong to the α-NaFeO2 structural family (R3m), as well as NaLaS2, which is derived from the disordered NaCl structural type (Fm3m). The determined structures were compared with known members of the group 1 as well as thallium(I) rare-earth sulfides by the standard tools of crystal-chemical analysis such as comparison of bond-valences, analysis of interatomic distances and comparison of the unit-cell parameters. The results indicate why the cubic structural type is limited to Li(+) and Na(+) members of the series only. The analysis has also revealed frequent problems in the reported crystal structures, especially in the determination of the K(+) compounds, probably due to severe absorption and different accuracy and sensitivity of various instruments. Intense diffuse scattering has been discovered in NaLaS2, which will be the subject of further investigation. The newly determined as well as already known structures are summarized, together with critical comments about possible errors in the previous structure determinations.

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