Ba4Al7Li28.08O26.92N1.08, the Barium Oxonitridolithoaluminate with a Highly Condensed LiO4 Tetrahedra Framework

The new compound Ba4Al7Li28.08O26.92N1.08 consists of AlO4/AlO3N tetrahedra, 10-fold coordinated Ba2+ cations, and a highly condensed edge-and corner-sharing LiO4 tetrahedra framework, which leads to a degree of condensation greater than 1. The first barium oxonitridolithoaluminate was synthesized by a high-temperature solid-state reaction in a weld-shut tantalum ampoule and the crystal structure has been determined by single-crystal X-ray diffraction. Ba4Al7Li28.08O26.92N1.08 crystallizes in the monoclinic space group P21/m (no. 11) with the lattice parameters a = 1052.41(3), b = 615.93(2), c = 1088.45(4) pm, beta = 98.86(1)degrees, and a volume of V = 0.69712(4) nm3. In addition, Ba4Al7Li28.08O26.92N1.08 doped with the activator ion Eu2+, exhibits a broad band emission with a maximum at lambda max = 524 nm (2.34 eV) with a fwhm of 112 nm (4373 cm-1/0.54 eV), which can be described by a superposition of two adjusted emission bands at lambda max = 515 nm (2.41 eV) with a fwhm of 70 nm (2704 cm-1/0.34 eV), and at lambda max= 574 nm (2.18 eV) with a fwhm of 127 nm (4127 cm-1/0.51 eV).

Automated summary

The new compound Ba4Al7Li28.08O26.92N1.08 consists of AlO4/AlO3N tetrahedra, Ba2+ cations with 10-fold coordination, and a highly condensed LiO4 tetrahedra framework. The crystal structure of Ba4Al7Li28.08O26.92N1.08 was determined by single-crystal X-ray diffraction. Ba4Al7Li28.08O26.92N1.08 belongs to the monoclinic space group P21/m (no. 11) with specific lattice parameters. Furthermore, Ba4Al7Li28.08O26.92N1.08 doped with Eu2+ activator ion exhibits a broad band emission with multiple adjusted emission bands.