Synthesis, crystal structure and optical properties of an indium phosphate K 3In 3P 4O 16

Abstract

An alkali-metal indium phosphate crystal, K 3In 3P 4O 16, has been synthesized by a high-temperature solution reaction and exhibits a new structure in the family of the alkali-metal indium phosphates system. Single-crystal X-ray diffraction analysis shows the structure to be monoclinic with space group P2 1/ n, and the following cell parameters: a=9.7003(18), b=9.8065(18), c=15.855(3) Å, β=90.346(3)°, V=1508.2(5) Å 3, Z=4, R=0.0254. It possesses three-dimensional [ In 3 ( PO 4 ) 4 ] n 3 - anionic frameworks with tunnels occupied by K + cations running along the a-axis. The emission and absorption spectra of the compound have been investigated. Additionally, the calculations of energy band structure, density of states, dielectric constants and refractive indexes have been performed with the density functional theory method. Also, the two-photon absorption spectrum is simulated by two-band model. The obtained results tend to support the experimental data.