Author:
Laval Jean-Paul,Taoudi Abdelkrim
Abstract
The first ternary BaF2–Ln(Y)F3–ZrF4 phases crystallizing near the composition range of fluoride glasses, namely Ba4YZr3F23 (barium yttrium fluoridozirconate) and isotypic Ba4LnZr3F23 (Ln = Yb, Er and Nd), have been synthesized. The crystal structure of Ba4YZr3F23 cannot be correctly determined in the centrosymmetric space group Pnma (R1 = 0.09); it is preferably described in the noncentrosymmetric space group Pn21
a (R1 = 0.028). All cations are located at y = 0.25–0.29 and 0.75–0.79. This new structure type is formed by infinite {[YZr3F23]8−}
n
columns associating, along [001], YF9 tricapped trigonal prisms, ZrF8 dodecahedra and ZrF7 polyhedra. These columns are interconnected via BaF10+1 and BaF12 irregular polyhedra.
Publisher
International Union of Crystallography (IUCr)
Subject
Materials Chemistry,Inorganic Chemistry,Physical and Theoretical Chemistry,Condensed Matter Physics