Synthesis of Mixed-Anion Fluorosulfide Ba₁₈F₁₈In₈S₂₁ and Comparison between Experimental and Theoretical Fluorine K-edge X-ray Absorption Near Edge Structure

Abstract

Mixed-anion fluoride compounds containing highly polarizable sulfide ions are less widely reported than comparable single-anion materials and have potential use in device applications. This study reports the synthesis of Ba₁₈F₁₈In₈S₂₁ and its crystal structure analysis by X-ray diffraction and electronic structure analysis by fluorine K-edge X-ray absorption spectroscopy. The solid-phase synthesis of Ba₁₈F₁₈In₈S₂₁ using indium sulfide as starting material was superior to that using indium metal and elemental sulfur and yielded a product with comparatively little impurity. The experimental fluorine K-edge X-ray absorption near edge structure of Ba₁₈F₁₈In₈S₂₁ was well-reproduced by the first principles calculations using the CASTEP program.