Preparation of (Ba, Sr)-Cu-In-N compounds and their crystal structures

Abstract

New compounds, Ba₈Cu₃In₄N₅, Sr₈Cu₃In₄N₅, Ba₁₄Cu₂In₄N₇, Ba₆In_4.72N₃ and Ba₁₉In₉N₉, were prepared with a Na flux by heating at 1023 K and 0.5 - 7 MPa of N₂ for 1 h, and by cooling from 1023 K to 823 K at a rate of 2 K/h. N atoms are surrounded by Ba or Sr and/or Cu atoms and situated in the octahedra of the metal atoms. The N-centered octahedra form layers, tunnels, or cages by sharing the apexes, edges and/or faces. Indium atoms exist as isolated, one-dimensional, or three-dimensional Zintl poly anions in the structures.