A new luminescent host material K₃GdB₆O₁₂. Synthesis, crystal structure and luminescent properties activated by Sm³⁺

A new borate compound K₃GdB₆O₁₂ has been prepared using a high temperature flux method and structurally characterized by single crystal X-ray diffraction analysis. The structure can be described as a three-dimensional framework that is composed of [B₅O₁₀]^5- groups, K⁺ ions and Gd³⁺ ions. In this structure, one crystallographic distinct site is mixed occupied by K and Gd atoms at the molar ratio of 1:1. Furthermore, Sm³⁺ ion was used as the activator to test primary of K₃GdB₆O₁₂ to be used as a luminescent host matrix. A series of phosphors K₃Gd_1-xB₆O₁₂:xSm³⁺ were synthesized by conventional solid-state reaction. The photoluminescence properties and concentration quenching of the prepared phosphors were investigated. The results show that K₃Gd_1-xB₆O₁₂:xSm³⁺ can be efficiently excited by near-UV light. K₃Gd_1-xB₆O₁₂:xSm³⁺ might be a promising candidate for visual display and solid-state lighting as an orange emission phosphor.