Crystal structure determination and characterization of Sm₃SiO₅F₃

Abstract

In this paper, we present the crystal structure of the novel compound Sm3SiO5F3. Single crystals were obtained using a high-pressure/high-temperature approach. Sm3SiO5F3 crystallizes in the triclinic space group P 1 ‾ $\bar{1}$ (aP24) with a = 6.1894(2), b = 7.1315(2), c = 7.3997(3) Å, α = 103.66(1), β = 98.06(1), γ = 90.16(1)°, V = 314.03(2) Å3, Z = 2 at T = 300 K and, to the best of our knowledge, presents a new structure type. BLBS and CHARDI calculations were used to assign oxidation states to the atoms, thus allowing us to differentiate between fluorine and oxygen atoms within the crystal structure. MAPLE calculations were carried out to support the structure solution. Electron microprobe measurements corroborate the ratio of Sm to Si and unequivocally prove the presence of Si within the compound. Despite various attempts, bulk synthesis of the compound could not be realized.

Luminescence Properties of Y3F[Si3O10]:Ln3+ (Ln = Eu, Tb, Er) with Thalenite-Type Host Lattice and Crystal Structure of Tm3F[Si3O10]

“…Three isolated [SiO 4 ] 4− tetrahedra occur in the mixed-valent fluoride ortho-oxosilicate Eu 5 F[SiO 4 ] 3 (≡ "Eu II 2 Eu III 3 F(Si 3 O 12 )") [10] with apatite-type structure, where all Si-O-Si bridges are lost. Moreover, discrete orthooxosilicate anions also dominate the structures of some oxide-fluoride derivatives, such as La 7 OF 7 [SiO 4 ] 3 [11] and Sm 3 OF 3 [SiO 4 ] [12].…”