Luminescence Properties of Nd-Doped Strontium Aluminate with Six Coordination Sites

Abstract

Neodymium-doped phosphors have been applied to laser materials due to their potential for high efficiency and compactness. Among them, neodymium-doped yttrium aluminum garnet (Nd:YAG) was widely used as a medium material for near-infrared solid-state lasers. In this study, we focused on a novel neodymium-doped strontium aliminate phosphor, Nd:Sr3Al2O6. This crystal, which has cubic system (Pa-3), has the potential as a transparent polycrystalline ceramic. Additionally, the phosphor contains six Sr2+ sites that neodymium ions substitute. We prepared this phosphor by conventional solid state reaction using SrCO3 (99.9%), γ-Al2O3 (99.9%), and Nd(NO3)3・6H2O (99.9%). These starting materials were mixed in an alumina mortar, and all mixtures were sintered under air atmosphere. The crystal structure of a prepared sample was characterized by using X-ray diffraction. The diffraction pattern of the sample agreed with that of JCPDS for Sr3Al2O6 (24-1187). Luminescence properties were estimated by using emission spectrum and lifetime. The 4f-4f emission of Nd3+ was broad compared with that of Nd:GdVO4, which has a broader emission band than that of Nd:YAG. Nd:Sr3Al2O6 is potentially applicable to Nd-doped solid-state laser with a broad emission band.