Study of an EuBO3–ScBO3 system and EuSc3(BO3)4, EuSc(BO3)2 orthoborates

Abstract

The EuBO₃–ScBO₃ system was investigated by solid state synthesis and DSC methods. In this system, a new EuSc(BO₃)₂ compound was found. It crystallizes in the R space group with unit cell parameters of a = 4.8939(1) Å and c = 16.2663(5) Å. Whereas another compound in the system EuSc₃(BO₃)₄ possesses two modifications: a low-temperature α-C2/c (a = 7.687(1) Å, b = 9.810(2) Å, c = 12.021(2) Å, and β = 105.379(4)°) and a high-temperature β-R32 (a = 9.7473(1) Å and c = 7.9205(2) Å). The α-EuSc₃(BO₃)₄ crystal was grown with LiBO₂–LiF flux, and β-EuSc₃(BO₃)₄ was obtained by the solid state synthesis. All of the obtained crystals exhibited typical Eu³⁺ luminescence spectra with peaks at 589 nm, 596 nm, 615 nm, 657 nm and 689 nm, which corresponded to the ⁵D₀ → ⁷F_J (J = 0, 1, 2 and 4) electron transitions. The strongest peak of luminescence was located at 615 nm and corresponded to the ⁵D₀ → ⁷F₀ transition.