The Synthesis, Structure, and Luminescent Properties of TmMgB(5)O(10) Crystals

TmMgB(5)O(10) spontaneous crystals were synthesized via the flux-growth technique from a K(2)Mo(3)O(10)-based solvent. The crystal structure of the compound was solved and refined within the space group P2(1)/n. The first principles calculations of the electronic structure reveal that TmMg-pentaborate with an ideal not defected crystal structure is an insulator with an indirect energy band gap of approximately 6.37 eV. Differential scanning calorimetry measurements and powder X-ray diffraction studies of heat-treated solids show that TmMgB(5)O(10) is an incongruent melting compound. A characteristic band of the Tm(3+) cation corresponding to the (3)H(6) → (1)D(2) transition is observed in the photoluminescence excitation spectra of TmMg-borate. The as-obtained crystals exhibit intense blue emission with the emission peaks centered at 455, 479, 667, and 753 nm. The most intensive band corresponds to the (1)D(2) → (3)F(4) transition. TmMgB(5)O(10) solids demonstrate the thermal stability of photoluminescence.